Synthesis and antitumor activity of erysolin and its metabolites.

Erysolin and its two metabolites which were found in blood, ERY-GSH and ERY-NAC, were synthesized by alkylation, amination, isothiocyanation and oxidation reactions from 1-bromo-4-chlorobutane and sodium methyl mercaptide. The reaction temperature, time, feed ratios and purification method were also optimized. The synthesis method was simple, green, safe and low-cost. Erysolin, ERY-GSH and ERY-NAC showed good antitumor activities against MCF-7, HeLa, HepG2, A549 and SW480 cells, which suggested that the antitumor mechanism of erysolin can also be clarified from its metabolites in addition to itself.

Electricity mediated plasmonic tip engineering on single Ag nanowire for SERS.

An electricity-mediated plasmonic engineering was applied on a single Ag nanowire to engineer its tip for surface-enhanced Raman scattering (SERS). Under this constant photoelectric field treatment, a significant sharpening of the tip and reduction of the surface fluctuation was observed for the Ag nanowire tip via in situ atomic force microscopy. A significant SERS signal enhancement was thus obtained after the tip engineering. The relevant dynamic mechanisms of the tip engineering, including the light-induced plasmonic phase transition and electrostatic force driven flow on the Ag nanowire tip are discussed in detail. It is expected that this type of tip engineering will greatly enhance the signal of single metal nanowire SERS probes and provide new insights into fabrication technologies for metal nanostructures.

Tunnel Structure Enhanced Polysulfide Conversion for Inhibiting "Shuttle Effect" in Lithium-Sulfur Battery.

The Lithium sulfur (Li-S) battery has a great potential to replace lithium-ion batteries due to its high-energy density. However, the "shuttle effect" of polysulfide intermediates (Li2S8, Li2S6, Li2S4, etc.) from the cathode can lead to rapid capacity decay and low coulombic efficiency, thus limiting its further development. Anchoring polysulfide and inhibiting polysulfide migration in electrolytes is one of the focuses in Li-S battery. It is well known that polar metal oxides-manganese oxides (MnO2) are normally used as an effective inhibitor for its polysulfide inhibiting properties. Considering the natural 1D tunnel structure, MnO2 with three kinds of typical tunnel-type were screened to study the effects of the tunnel size on the adsorption capacity of polysulfide. We found that MnO2 with larger tunnel sizes has stronger chemisorption capacity of polysulfide. It promotes the conversion of polysulfide, and corresponding cathode exhibits better cycle reliability and rate performance in the cell comparison tests. This work should point out a new strategy for the cathode design of advanced Li-S battery by controlling the tunnel size.

Influence of traditional Chinese medicines on the in vivo metabolism of lopinavir/ritonavir based on UHPLC-MS/MS analysis.

A fast, reliable, and cost-effective liquid chromatography-tandem mass spectrometry method was established to determine the effects of the traditional Chinese medicine employed to treat coronavirus disease 2019, namely, Lianhua Qingwen granules, Huoxiang Zhengqi capsules, Jinhua Qinggan granules, Shufeng Jiedu capsules, and Angong Niuhuang pills, on the pharmacokinetics of lopinavir/ritonavir in rats. Blood samples were prepared using the protein precipitation method and atazanavir was selected as the internal standard (IS). Separation was performed on an Agilent ZORBAX eclipse plus C18 (2.1 mm × 50 mm, 1.8 µm) column using acetonitrile and water containing 0.1% formic acid as the mobile phase for gradient elution. The flow rate was 0.4 mL/min and the injection volume was 2 µL. Agilent Jet Stream electrospray ionization was used for mass spectrometry detection under positive ion multiple reaction monitoring mode at a transition of m/z 629.3→447.3 for lopinavir, m/z 721.3→296.1 for ritonavir, and m/z 705.4→168.1 for the IS. The method showed good linearity in the concentration range of 25-2500 ng/mL (r=0.9981) for lopinavir and 5-500 ng/mL (r=0.9984) for ritonavir. The intra-day and inter-day precision and accuracy were both within ±15%. Items, such as dilution reliability and residual effect, were also within the acceptable limits. The method was used to determine the effects of five types of traditional Chinese medicines on the pharmacokinetics of lopinavir/ritonavir in rats. The pharmacokinetic results showed that the half-life of ritonavir in the groups administered Lianhua Qingwen granules and Huoxiang Zhengqi capsules combined with lopinavir/ritonavir was prolonged by approximately 1.5- to 2-fold relative to that in the control group. Similarly, the pharmacokinetic parameters of lopinavir were altered. Overall, the results of this study offer important theoretical parameters for the effective clinical use of five types of traditional Chinese medicines combined with lopinavir/ritonavir to reduce the occurrence of clinical adverse reactions.

Sonication induced amorphisation in Ag nanowires.

It has long been conjectured that pure-element face-centred cubic (fcc) metals can be transformed into a glassy state by deformation at ultra-high strain rates. However, when an impact force is applied at the nanoscale, deformation-induced melting prevents observations of fcc metal amorphisation. Here we propose a sonication treatment of Ag nanowires (fcc) and confirmed amorphisation induced by high strain rates at bent areas of the Ag nanowires. Owing to the mismatch of the deformation modes between the core and the surface, we observed a diameter related increase of the ductility of Ag nanowires under deformation at ultra-high strain rates generated by sonication. The sonication-prepared amorphous Ag was stable at room temperature. Amorphous Ag at the bent areas was highly reactive and was readily recrystallized under light illumination or vulcanised. Our study verifies the occurrence of high strain rate induced amorphisation in pure fcc MGs and provides a powerful tool for mechanical studies on metal nanomaterials under extremely high strain rates and forces.

Enhanced High-Temperature Mechanical Properties of Al⁻Cu⁻Li Alloy through T1 Coarsening Inhibition and Ce-Containing Intermetallic Refinement.

The effects of the addition of 0.29 wt% Ce on the high-temperature mechanical properties of an Al-Cu-Li alloy were investigated. Ce addition contributes to T1 (Al2CuLi) phase coarsening inhibition and Ce-containing intermetallic refinement which greatly improved the thermal stability and high-temperature deformation uniformity of this alloy. On the one hand, small Ce in solid solution and segregation at phase interface can effectively prevent the diffusion and convergence of the main element Cu on T1 phase during thermal exposure. Therefore, the thermal stability of Ce-containing alloy substantiality improves during thermal exposure at the medium-high-temperature stage (170 °C to 270 °C). On the other hand, the increment of the tensile elongation in Ce-containing alloy is much greater than that in Ce-free alloy at high temperatures tensile test, because the refined Al8Cu4Ce intermetallic phase with high-temperature stability are mainly located in the fracture area with plastic fracture characteristics. This work provides a new method for enhancing high-temperature mechanical properties of Al-Cu-Li alloy which could be used as a construction material for high-temperature structural components.

Ultrasonic Modification of Ag Nanowires and Their Applications in Flexible Transparent Film Heaters and SERS Detectors.

Ultrasonic morphology modification of silver (Ag) nanowires and their applications in transparent film heaters for defogging in electric vehicles and surface-enhanced Raman scattering (SERS) detectors have been studied. With 10 min ultrasonic treatment of Ag nanowires, the electro-thermal conversion capability of Ag nanowire based transparent film heaters is efficiently improved (about 50% increase in temperature rise), which can be mainly attributed to the cross-section area reduction and the serious agglomerations of the ultrasonic modified Ag nanowire films. Furthermore, the bending or fracture caused by deformation of Ag nanowires after ultrasonic treatment provides more hot spots for SERS, and therefore lead to a significant SERS signal enhancement. This work not only greatly improves the performance of Ag nanowire based transparent film heaters and SERS detectors, but provides a new way for the functional modification of Ag nanowires.