Sodium storage behavior and long cycle stability of boron-doped carbon nanofibers for sodium-ion battery anodes

A double heteroatom doping strategy is proposed to synthesize boron- and nitrogen-doped heteroatom carbon nanofibers (BNC NFs) as anode materials for sodium-ion batteries (SIBs). The specific capacity and rate performance of the BNC NF anode are higher than those of the NC NF anode. Particularly, the composite containing 5 wt% boric acid provides the highest reversible capacity of 249 mAh g−1 at a current density of 0.02 A g−1 and excellent cyclic stability of 144 mAh g−1 at 2 A g−1 after 3000 cycles. The excellent cyclic performance of the BNC NFs can be attributed to the defect-rich nanostructure derived by optimally doping boron under annealing, which is conducive to accelerating ion transport and introducing additional Na-ion storage active sites. The excellent capacity and long cycle stability of the full cell SIBs comprising the optimized BNC NFs anode and Na3V2(PO4)3 cathode suggest the promising potential of B-doped C NFs as anodes for rechargeable Na-ion batteries. © 2022 Elsevier LtdFALS

Abnormally High-Lithium Storage in Pure Crystalline C-60 Nanoparticles

Li+ intercalates into a pure face-centered-cubic (fcc) C-60 structure instead of being adsorbed on a single C-60 molecule. This hinders the excess storage of Li ions in Li-ion batteries, thereby limiting their applications. However, the associated electrochemical processes and mechanisms have not been investigated owing to the low electrochemical reactivity and poor crystallinity of the C-60 powder. Herein, a facile method for synthesizing pure fcc C-60 nanoparticles with uniform morphology and superior electrochemical performance in both half- and full-cells is demonstrated using a 1 m LiPF6 solution in ethylene carbonate/diethyl carbonate (1:1 vol%) with 10% fluoroethylene carbonate. The specific capacity of the C-60 nanoparticles during the second discharge reaches approximate to 750 mAh g(-1) at 0.1 A g(-1), approximately twice that of graphite. Moreover, by applying in situ X-ray diffraction, high-resolution transmission electron microscopy, and first-principles calculations, an abnormally high Li storage in a crystalline C-60 structure is proposed based on the vacant sites among the C-60 molecules, Li clusters at different sites, and structural changes during the discharge/charge process. The fcc of C-60 transforms tetragonal via orthorhombic LixC60 and back to the cubic phase during discharge. The presented results will facilitate the development of novel fullerene-based anode materials for Li-ion batteries

Renal and cardiac effects of the PDE9 inhibitor BAY 73-6691 in 5/6 nephrectomized rats.

We examined the effects of the PDE9 inhibitor BAY 73-6691 on the kidney and heart for the first time in a 5/6 nephrectomy animal model using BAY 73-6691 dosages known to be effective in other rat disease models. We did not observe any relevant effects of the PDE9 inhibitor BAY 73-6691 on renal function, renal histology, and renal disease-related pathways and gene expression in 5/6 nephrectomy rats. In addition, the effects of the PDE9 inhibitor BAY 73-6691 on the heart of 5/6 nephrectomy rats were mild. Except for cardiomyocyte size, BAY 73-6691 had no effect on other cardiac histological parameters, cardiac function, and disease-related genes and pathways. </p

Supplemental figure S1 and S2

Supplemental figure S1. Time course of the animal study. Uni-Nx: Unilateral nephrectomy of the right kidney; Poles amputation: Amputation of the poles of the left kidney; BP: Blood pressure; Blood 1 and Blood 2 were taken from retro-orbital venous plexus; Blood 3 was taken from the abdominal aorta. Supplemental figure S2. The differentially expressed genes in kidney detected by RNA-seq transcriptome. (A) Venn diagram of the differentially expressed genes from RNA-seq transcriptome for 5/6Nx + PBO, 5/6Nx + TELM, 5/6Nx + 3mg EMPA and 5/6Nx + 15mg EMPA groups. The circles represent the total number of statistically significant different signals (P value 1) in 5/6 Nx + 3mg EMPA, 5/6 Nx + 15mg EMPA and 5/6 Nx + TELM groups in comparison to 5/6 Nx + PBO in kidney according to RNA-seq transcriptome data. (B, C, D, E) Volcano plot of RNA-seq transcriptome data displaying the pattern of gene expression values for every treatment group relative to 5/6Nx + PBO group. The genes are coloured if they pass the thresholds for p value=0.05 and log2 (fold change) = ±1, orange if they are upregulated and blue if they are downregulated. Significantly differently regulated genes confirmed by qRT-PCR were labelled. (B) 5/6Nx + 3mg EMPA versus 5/6Nx+PBO; (C) 5/6Nx + 15mg EMPA versus 5/6Nx+PBO; (D) 5/6Nx + TELM versus 5/6Nx+PBO; (E) 5/6Nx + PBO versus sham + PBO. Sham: Sham operation; 5/6Nx: 5/6 nephrectomized rat model; PBO: Placebo; TELM: Telmisartan; EMPA: Empagliflozin; qRT-PCR: Quantitative Reverse Transcription Polymerase Chain Reaction. </p

Accelerated lake expansion on the Tibetan Plateau in the 2000s: Induced by glacial melting or other processes?

ccelerated lake expansion in the 2000s has been confirmed by both dramatic lake-area increases (for 312 lakes larger than 10 km2) derived from optical images, and rapid water-level rises (for 117 lakes with water-level data) measured by satellite altimetry. However, the underlying climate causes remain unclear. This paper analyzes the relationship between the water-level changes of lakes on the plateau and the potential driving factors, such as the glacier meltwater supply and a dependency on precipitation and runoff over the whole plateau and in each zone. The results show that the rates of change of non-glacier-fed lakes in the 2000s were as high as those of glacier-fed lakes across the whole plateau and the lake-level changes were closely associated with the lake supply coefficients (the basin/lake area ratio). The lake variations agreed well with the spatial pattern of precipitation changes. However, in different zones, especially at around 33°N north of the plateau, glacier-fed lakes did exhibit faster lake level increases than no-glacier-fed lakes, indicating that the presence of a glacier meltwater supply augmented the precipitation-driven lake expansions in these areas. Despite the absence of quantitative modeling due to limited data availability, this study provides qualitative support that the lake expansions on the Tibetan Plateau in the 2000s have been driven primarily by changes in precipitation and evapotranspiration and not solely by the effect of glacier wastage.Geoscience & Remote SensingCivil Engineering and Geoscience