High-temperature magnetically topological candidate material Mn3Bi2Te6.

The Mn-Bi-Te family displaying magnetism and non-trivial topological properties has received extensive attention. Here, we predict that the antiferromagnetic structure of Mn3Bi2Te6with three MnTe layers is energetically stable and the magnetic energy difference of Mn-Mn is enhanced four times compared with that in the single MnTe layer of MnBi2Te4. The predicted Néel transition point is raised to 102.5 K, surpassing the temperature of liquid nitrogen. The topological properties show that with the variation of the MnTe layer from a single layer to three layers, the system transforms from a non-trivial topological phase to a trivial topological phase. Interestingly, the ferromagnetic state of Mn3Bi2Te6is a topological semimetal and it exhibits a topological transition from trivial to non-trivial induced by the magnetic transition. Our results enrich the Mn-Bi-Te family system, offer a new platform for studying topological phase transitions, and pave a new way to improve the working temperature of magnetically topological devices.

50C Fast-Charge Li-Ion Batteries using a Graphite Anode.

Li-ion batteries have made inroads into the electric vehicle market with high energy densities, yet they still suffer from slow kinetics limited by the graphite anode. Here, electrolytes enabling extreme fast charging (XFC) of a microsized graphite anode without Li plating are designed. Comprehensive characterization and simulations on the diffusion of Li+ in the bulk electrolyte, charge-transfer process, and the solid electrolyte interphase (SEI) demonstrate that high ionic conductivity, low desolvation energy of Li+ , and protective SEI are essential for XFC. Based on the criterion, two fast-charging electrolytes are designed: low-voltage 1.8 m LiFSI in 1,3-dioxolane (for LiFePO4 ||graphite cells) and high-voltage 1.0 m LiPF6 in a mixture of 4-fluoroethylene carbonate and acetonitrile (7:3 by vol) (for LiNi0.8 Co0.1 Mn0.1 O2 ||graphite cells). The former electrolyte enables the graphite electrode to achieve 180 mAh g-1 at 50C (1C = 370 mAh g-1 ), which is 10 times higher than that of a conventional electrolyte. The latter electrolyte enables LiNi0.8 Co0.1 Mn0.1 O2 ||graphite cells (2 mAh cm-2 , N/P ratio = 1) to provide a record-breaking reversible capacity of 170 mAh g-1 at 4C charge and 0.3C discharge. This work unveils the key mechanisms for XFC and provides instructive electrolyte design principles for practical fast-charging LIBs with graphite anodes.

New oxindole alkaloids with selective osteoclast inhibitory activity from Gelsemium elegans.

A new alkaloid 14-hydroxygelseziridine (1), along with four known oxindoles (2-5), was isolated and characterized from the well-known toxic medicine Gelsemium elegans. Their structures were elucidated by means of spectroscopic techniques and quantum chemistry calculations. Structurally, new compound 1 has a three membered oxygen ring at N-4/C-20. All compounds were tested for osteoclast (MOC-1) inhibitory activity in vitro. Compound 2 exhibited the selective osteoclast inhibitory activity. Flow cytometry revealed that the apoptosis of osteoclasts induced by 2. Furthermore, the PCR bioassay suggested that compound 2 may activate the apoptotic pathway of osteoclasts by reducing the expression of IL-6 and c-Jun, and increasing caspase 9. This work provided the evidence for the rationality as the traditional treatment for bone related diseases of G. elegans, and shed a new light on its further research.

Indocyanine green conjugated lipid microbubbles as an ultrasound-responsive drug delivery system for dual-imaging guided tumor-targeted therapy.

Herein, a multifunctional traceable and ultrasound-responsive drug targeted delivery system based on indocyanine green (ICG) and folic acid (FA) covalently conjugated lipid microbubbles (ILMBs-FA) is proposed. After encapsulation of the anticancer drug resveratrol (RV), the composite (RILMBs-FA) with fluorescence and ultrasound imaging capacity was studied for highly sensitive dual-imaging guided tumor targeted therapy. The resulting RILMBs-FA with an average particle size of 1.32 ± 0.14 µm exhibited good stability and biocompatibility characteristics. The RILMBs-FA featured a high RV loading ratio and the encapsulated RV has been demonstrated to be released from the microbubbles triggered by ultrasound (US) waves. In addition, it was found that the linked FA could facilitate a high cellular uptake of RILMBs-FA via the FA receptor-mediated endocytosis pathway. Compared to free RV and RILMBs, RILMBs-FA with US irradiation demonstrated a more significant tumor cell-killing efficacy mediated by apoptosis in vitro. Eight hours post intravenous injection of RILMBs-FA, the composites showed maximum accumulation in tumorous tissues according to in vivo fluorescence and US images. This ultimately led to the best tumor inhibition effect among all tested drugs under US irradiation. In vivo biosafety evaluations showed that RILMBs-FA featured high biocompatibility characteristics and no significant systemic toxicity over the course of one month. Taken in concert, these results demonstrate the versatility of this drug delivery system with dual-imaging and ultrasound-triggered drug release characteristics for potential future applications in cancer theranostics.