Anti-fibrosis attributes: UHPLC-MS/MS-based pharmacokinetics profiling of a novel autotaxin inhibitor with excellent in vivo efficacy in rat

3,4-Difluorobenzyl(1-ethyl-5-(4-((4-hydroxypiperidin-1-yl)-methyl)thiazol-2-yl)-1H-indol-3-yl)carbamate (NAI59), a small molecule with outstanding therapeutic effectiveness to anti-pulmonary fibrosis, was developed as an autotaxin inhibitor candidate compound. To evaluate the pharmacokinetics and plasma protein binding of NAI59, a UPLC–MS/MS method was developed to quantify NAI59 in plasma and phosphate-buffered saline. The calibration curve linearity ranged from 9.95 to 1990.00 ng/mL in plasma. The accuracy was −6.8 to 5.9%, and the intra- and inter-day precision was within 15%. The matrix effect and recovery, as well as dilution integrity, were within the criteria. The chromatographic and mass spectrometric conditions were also feasible to determine phosphate-buffered saline samples, and it has been proved that this method exhibits good precision and accuracy in the range of 9.95–497.50 ng/mL in phosphate-buffered saline. This study is the first to determine the pharmacokinetics, absolute bioavailability, and plasma protein binding of NAI59 in rats using this established method. Therefore, the pharmacokinetic profiles of NAI59 showed a dose-dependent relationship after oral administration, and the absolute bioavailability in rats was 6.3%. In addition, the results of protein binding showed that the combining capacity of NAI59 with plasma protein attained 90% and increased with the increase in drug concentration.     

Effects of Thieno[3,2-b]thiophene Number on Narrow-Bandgap Fused-Ring Electron Acceptors

Chinese Journal of Polymer Science - We synthesize and compare four near-infrared absorbing fused-ring electron acceptors named as nTTIC (n=2, 3, 4, and 5), based on different number of...     

Synthesis and Characterization of Novel Liquid Crystalline Epoxides with Lateral Substituent Showing Imposing Shape Memory Properties

In this work, a series of novel shape memory liquid crystalline (LC) epoxides with lateral substituent were prepared and characterized. Dynamic mechanical analysis (DMA) and shape memory testing were used to investigate on the thermo-mechanical properties and shape memory effects of prepared samples. The results showed that the modulus in the rubbery region (E_R ) decreased as the length of lateral alkyl group increases. And more than 95% of the deformation can be fixed as the sample was cooled down below the glass transition temperature (T_g), which was determined by differential scanning calorimetry (DSC) measurement, and can be recovered completely as heating. Effects of the curing agent and substituent on the shape memory behavior were also studied. We found that LC epoxides cured by aromatic diamine have a higher recovery speed. The recovering speeds of the shape memory decreased as the length of lateral alkyl group inscreased. The local ordered structures and the lateral substituent played an important role in shape memory effects.     

Synthesis of Fluorescent Carbon Dots and Their Application in Ascorbic Acid Detection

Water-soluble fluorescent carbon dots (CDs) were synthesized by a hydrothermal method using citric acid as the carbon source and ethylenediamine as the nitrogen source. The repeated and scale-up synthetic experiments were carried out to explore the feasibility of macroscopic preparation of CDs. The CDs/Fe³⁺ composite was prepared by the interaction of the CDs solution and Fe³⁺ solution. The optical properties, pH dependence and stability behavior of CDs or the CDs/Fe³⁺ composite were studied by ultraviolet spectroscopy and fluorescence spectroscopy. Following the principles of fluorescence quenching after the addition of Fe³⁺ and then the fluorescence recovery after the addition of asorbic acid, the fluorescence intensity of the carbon dots was measured at λex = 360 nm, λem = 460 nm. The content of ascorbic acid was calculated by quantitative analysis of the changing fluorescence intensity. The CDs/Fe³⁺ composite was applied to the determination of different active molecules, and it was found that the composite had specific recognition of ascorbic acid and showed an excellent linear relationship in 5.0–350.0 μmol·L⁻¹. Moreover, the detection limit was 3.11 μmol·L⁻¹. Satisfactory results were achieved when the method was applied to the ascorbic acid determination in jujube fruit. The fluorescent carbon dots composites prepared in this study may have broad application prospects in a rapid, sensitive and trace determination of ascorbic acid content during food processing.     

Construction of Shallow Surface States through Light Ni Doping for High‐Efficiency Photocatalytic Hydrogen Production of CdS Nanocrystals

Ni‐doped CdS nanowires were synthesized by a simple one‐step method. X‐ray diffraction, X‐ray photoelectron spectroscopy, and photoluminescence spectroscopy confirmed that light Ni doping can form shallow surface states due to the presence of substitutional Ni ions, and heavy Ni doping can form deep surface states due to the presence of interstitial Ni ions. Surface photovoltage spectroscopy and transient photovoltage measurements revealed that the shallow surface states can prolong the lifetime of the photogenerated charge carriers, whereas the deep surface states lead to recombination of the photogenerated charge carriers. The relationship between different surface states and the photocatalytic performance of CdS nanocrystals are discussed. The enhanced density of shallow surface states due to light Ni doping significantly promotes photocatalytic H₂ production.     

Chiral Metal–Organic Frameworks Bearing Free Carboxylic Acids for Organocatalyst Encapsulation

Two chiral carboxylic acid functionalized micro‐ and mesoporous metal–organic frameworks (MOFs) are constructed by the stepwise assembly of triple‐stranded heptametallic helicates with six carboxylic acid groups. The mesoporous MOF with permanent porosity functions as a host for encapsulation of an enantiopure organic amine catalyst by combining carboxylic acids and chiral amines in situ through acid–base interactions. The organocatalyst‐loaded framework is shown to be an efficient and recyclable heterogeneous catalyst for the asymmetric direct aldol reactions with significantly enhanced stereoselectivity in relative to the homogeneous organocatalyst.     

酸性金属氧化物对锰铈氧化物催化剂脱硝温度窗口的调控作用

利用溶胶-凝胶法,采用三种酸性金属氧化物（氧化铌、氧化钨和氧化钼）对锰铈复合氧化物催化剂进行了改性. 测试了催化剂的氮氧化物选择性催化还原（SCR）活性,以筛选对应不同温度窗口的合适酸性氧化物改性剂. 同时评价了催化剂的NO氧化和NH₃氧化活性. 利用X射线衍射、BET比表面积测试、H₂程序升温还原、NH₃/NO_x程序升温脱附和NH₃/NO_x吸附红外光谱等手段对催化剂进行了表征. MnO_x-CeO₂催化剂表现出良好的低温（100-150 ℃）活性. 酸性金属氧化物的添加削弱了催化剂的氧化还原特性,从而抑制了NH₃的活化和NO₂辅助的快速SCR反应. 与此同时,相对高温（250-350 ℃）区NH₃的氧化也受到了抑制,B酸和L酸上的NH₃吸附得以增强. 因此,催化剂的SCR脱硝温度窗口向高温移动,改性效果Nb₂O₅ < WO₃ < MoO₃.     

Natural Soft/Rigid Superlattices as Anodes for High-Performance Lithium-Ion Batteries

Volume expansion and poor conductivity are two major obstacles that hinder the pursuit of the lithium-ion batteries with long cycling life and high power density. Herein, we highlight a misfit compound PbNbS₃ with a soft/rigid superlattice structure, confirmed by scanning tunneling microscopy and electrochemical characterization, as a promising anode material for high performance lithium-ion batteries with optimized capacity, stability, and conductivity. The soft PbS sublayers primarily react with lithium, endowing capacity and preventing decomposition of the superlattice structure, while the rigid NbS₂ sublayers support the skeleton and enhance the migration of electrons and lithium ions, as a result leading to a specific capacity of 710 mAh g⁻¹ at 100 mA g⁻¹, which is 1.6 times of NbS₂ and 3.9 times of PbS. Our finding reveals the competitive strategy of soft/rigid structure in lithium-ion batteries and broadens the horizons of single-phase anode material design.     

可控化学腐蚀法制备碳化硅量子点及其表面修饰

通过可控的化学腐蚀法完成了对碳化硅量子点的制备,而后经超声空化作用及高速层析裁剪获得水相的碳化硅量子点溶液,利用化学偶联法,一步实现了SiC量子点的表面物化特性调控.通过对制备工艺参数调整前后量子点微观形貌、光谱特性的表征,结果表明:腐蚀次数、腐蚀剂组分及腐蚀剂配比是影响碳化硅量子点光致发光效率的主要因素,调整腐蚀次数与腐蚀剂组分的配比,同时加入偶联剂分析纯硫酸,当以V(HF):V(HNO3):V(H2 SO4)=6:1:1(体积比)的组分及比例腐蚀球磨后的β-SiC粉体时,制备出的水相碳化硅量子点光致发光相对强度最为理想.同时对碳化硅量子点表面巯基的形成机制与修饰稳定性进行了初步分析.     

Effects on the evolution of microstructure and properties of low-silicon cast aluminum alloys in service

ABSTRACT

The microstructure evolution and property change of four kinds of low silicon cast aluminum alloy exposed to heat for 0–50?h at 200°C were studied by means of Brinell hardness test, tensile property test, friction and wear property test and XRD analysis. The results show that with increasing thermal exposure time, the tensile strength of each group of samples decreased and the amount of wear increased. The tensile strength of samples with more Si content decreased slowly. When the time increased to 50?h, the increase of wear loss was the largest. The hardness of samples after thermal exposure increases compared with that before thermal exposure. The residual stress of (311) diffraction crystal surface of AlSi3.5Mg0.66 under different thermal exposure time was measured. The type of residual stress changed from residual tensile stress to residual compressive stress after thermal exposure. There is an abnormal phenomenon that the hardness of the sample increased and the amount of wear increased, and it is evident that the distribution of residual stress was inhomogeneous after thermal exposure. It is found that with increasing thermal exposure time to 50?h, the average lattice distortion ε of the low-index crystal plane and the high-index crystal plane in the aluminum alloys gradually increased.