Quantum Mechanical-Based Stability Evaluation of Crystal Structures for HIV-Targeted Drug Cabotegravir

The long-acting parenteral formulation of the HIV integrase inhibitor cabotegravir (GSK744) is currently being developed to prevent HIV infections, benefiting from infrequent dosing and high efficacy. The crystal structure can affect the bioavailability and efficacy of cabotegravir. However, the stability determination of crystal structures of GSK744 have remained a challenge. Here, we introduced an ab initio protocol to determine the stability of the crystal structures of pharmaceutical molecules, which were obtained from crystal structure prediction process starting from the molecular diagram. Using GSK744 as a case study, the ab initio predicted that Gibbs free energy provides reliable further refinement of the predicted crystal structures and presents its capability for becoming a crystal stability determination approach in the future. The proposed work can assist in the comprehensive screening of pharmaceutical design and can provide structural predictions and stability evaluation for pharmaceutical crystals.     

Utilization of Hematite Particles for Economical Removal of o-xylene in a High-Temperature Gas-Solid Reactor

To establish a novel approach for VOCs resource utilization, coupled o-xylene oxidation and hematite reduction was investigated in this study in a high-temperature gas-solid reactor in the temperature range 300–700 °C. As the o-xylene-containing inert gas (N₂) stream traveled through the hematite particle bed, its reaction behavior was determined in programmed heating and constant temperature modes. Consequently, the effect of bed temperature, flow rate and o-xylene inlet concentration on both o-xylene removal performance and degree of hematite reduction was studied. The raw hematite and solid products were analyzed by TGA, XRF, XRD and SEM-EDS. The results showed that a temperature above 300 °C was required to completely eliminate o-xylene by hematite, and both o-xylene removal capacity and degree of hematite reduction at 5% breakthrough points enhanced on increasing the temperature and decreasing the flow rate. The increment in temperature from 300 °C to 700 °C led to a gradual reduction of Fe₂O₃ to Fe₃O₄, FeO and metallic iron. Thus, this study provides a novel, economic and promising technology for treating the VOC pollutants.     

靛红参与的多组分反应在螺杂环化合物合成中的研究新进展

综述了近几年来利用靛红代替芳香醛参与多组分反应,并合成相关螺杂环化合物的最新研究进展,同时还对其发展方向加以展望.     

Molecular structure determination of solid carbon dioxide phase IV at high pressures and temperatures based on Møller-Plesset perturbation theory

Carbon dioxide has attracted considerable attention owing to its physics and abundant polymorphs. Despite decades of extensive experiments and theoretical simulations, the structure and properties of carbon dioxide under extreme pressures and temperatures are yet to be properly understood. Particularly, the intermediate phase IV of solid carbon dioxide, which separates the molecular phases at low pressures from the non-molecular phases at high pressures, has not been fully investigated, and its structure remains controversial. Here, based on the second-order Møller-Plesset perturbation (MP2) theory and the embedded fragment method, we study the crystal structure, equation of state, and Raman spectra of solid carbon dioxide phase IV at high pressures and temperatures. We demonstrate that the solid carbon dioxide phase IV is a molecular structure that remains in a molecular state rather than the bent state shown in other literature works, which is consistent with the experimental work by Datchi et al and denies the observed results by Park et al. The proposed work is of great significance in determining the structure of the high-pressure phases of carbon dioxide and further exploring the new phase of molecular crystals.     

Voltammetric studies on the interaction of epinephrine with DNA base on a glassy carbon electrode modified with Au nanoparticles

Ionics - The interaction of epinephrine (EP) with DNA, including double-strand DNA (dsDNA) and single-strand DNA (ssDNA) were investigated both in Mcllvaine buffer solution and on a glassy carbon...     

Protein and mRNA Delivery Enabled by Cholesteryl‐Based Biodegradable Lipidoid Nanoparticles

Developing safe and efficient delivery systems for therapeutic biomacromolecules is a long‐standing challenge. Herein, we report a newly developed combinatorial library of cholesteryl‐based disulfide bond‐containing biodegradable cationic lipidoid nanoparticles. We have identified a subset of this library which is effective for protein and mRNA delivery in vitro and in vivo. These lipidoids showed comparable transfection efficacies but much lower cytotoxicities compared to the Lpf2k in vitro. In vivo studies in adult mice demonstrated the successful delivery of genome engineering protein and mRNA molecules in the skeletal muscle (via intramuscular injection), lung and spleen (via intravenous injection), and brain (via lateral ventricle infusion).     

IR kinetic spectroscopy investigation of the CH4 + O(1D) reaction

The branching of the title reaction into several product channels has been investigated quantitatively by laser infrared kinetic spectroscopy for CH(4) and CD(4). It is found that OH (OD) is produced in 67 +/- 5% (60 +/- 5%) yield compared to the initial O((1)D) concentration. H (D) product is produced in 30 +/- 10%(35 +/- 10%). H(2)CO is produced in 5% yield in the CH(4) system (it was not possible to measure the CD(2)O yield in the CD(4) case). D(2)O is produced in 8% yield in the CD(4) system (it was not feasible to measure the H(2)O yield). The ratio of the overall rate constant of the CD(4) reaction to the overall rate constant of the O((1)D) + N(2)O reaction was determined to be 1.2(5) +/- 0.1. A measurement of the reaction of O((1)D) with NO(2) gave 1.3 x 10(-10) cm(3) molecule(-1) s(-1) relative to the literature values for the rate constants of O((1)D) with H(2) and CH(4). Hot atom effects in O((1)D) reactions were observed.     

Antimicrobial finishing of cotton textile based on water glass by sol–gel method

A low temperature and cost-effective process for antimicrobial finishing of cotton textiles has been developed by sol–gel method. The antimicrobial treatment was performed by treating cotton textile with silica sols from water glass and then with silver nitrate solution. The antimicrobial activity was determined by using E. coli as a model for Gram-negative bacteria. The results showed that the treated textile has an excellent antimicrobial effect and laundering durability. SEM analysis showed coarse surface morphological change on the water glass treated cotton textile. The residual concentration of silver ion on fabrics was informed by ICP-MS. XPS results indicated that two different states of silver were present on the surface of the antimicrobial textile.     

水介质中碱性离子液体[bmim][OH]催化下一锅三组分合成螺杂环衍生物

在水相中碱性离子液体[bmim][OH]催化作用下,由苊醌、丙二腈/氰乙酸乙酯和β-二酮三组分“一锅法”合成了一系列螺杂环化合物,产物的结构通过1H NMR,IR和MS表征.该方法条件温和,操作简单,后处理方便,反应时间短,对环境友好,且催化剂廉价易得.     

Improvement of hydrophobic properties of silk and cotton by hexafluoropropene plasma treatment

Plasma surface-treatment of silk and cotton fabrics were carried out in a hexafluoropropene (C₃F₆) atmosphere under different experimental conditions. Analysis of the treated fibers by X-ray photoelectron spectroscopy (XPS) indicated about 50 at% fluorine atoms were incorporated in the surface structure of two fibers and confirmed the presence of -CF, -CF₂, -CF₃ groups on the surface. After water-washing and alcohol-extraction, though partial loss of fluorine from the surface has been observed, contact angle and wet-out time measurements on the fibers still show much improved hydrophobic properties. The other properties of the treated fabrics, such as water vapor permeability and tensile strength were also evaluated.