Chitosan hydrogel encapsulated with LL-37 peptide promotes deep tissue injury healing in a mouse model

Background:LL-37 peptide is a member of the human cathelicidin family,and has been shown to promote the healing of pressure ulcers.However,the low stability of this peptide within the wound environment limits its clinical use.Chitosan(CS)hydrogel is commonly used as a base material for wound dressing material.Methods:CS hydrogel(2.5%w/v)was encapsulated with LL-37.Cytotoxicity of the product was examined in cultured NIH3 T3 fibroblasts.Effects on immune response was examined by measuring tumor necrosis factor-α(TNF-α)release from RAW 264.7 macrophages upon exposure to lipopolysaccharides.Antibacterial activity was assessed using Staphylococcus aureus.Potential effect on pressure ulcers was examined using a mouse model.Briefly,adult male C57 BL/6 mice were subjected to skin pressure using magnets under a 12/12 h schedule for 21 days.Mice were randomized to receive naked LL-37(20μg),chitosan gel containing 20μg LL-37(LL-37/CS hydrogel)or hydrogel alone under the ulcer bed(n=6).A group of mice receiving no intervention was also included as a control.Results:LL-37/CS hydrogel did not affect NIH3 T3 cell viability.At a concentration of 1–5μg/ml,LL-37/CS inhibited TNF-αrelease from macrophage.At 5μg/ml,LL-37/CS inhibited the growth of Staphylococcus aureus.The area of the pressure ulcers was significantly lower in mice receiving LL-37/CS hydrogel in comparison to all other 3 groups on days 11(84.24%±0.25%),13(56.22%±3.91%)and 15(48.12%±0.28%).Histological examination on days 15 and 21 showed increased epithelial thickness and density of newly-formed capillary with naked LL-37 and more so with LL-37/CS.The expression of key macromolecules in the process of angiogenesis(i.e.,hypoxia inducible factor-1α(HIF-1α)and vascular endothelial growth factor-A(VEGF-A))in wound tissue was increased at both the mRNA and protein levels.Conclusion:Chitosan hydrogel encapsulated with LL-37 is biocompatible and could promote the healing of pressure ulcers.

Development and characterization of a guinea pig model for Marburg virus

The Angolan strain of Marburg virus （MARV/Ang） can cause lethal disease in humans with a case fatality rate of up to 90%, but infection of immunocompetent rodents do not result in any observable symptoms. Our previous work includes the development and characterization of a MARV/Ang variant that can cause lethal disease in mice （MARV/Ang-MA）, with the aim of using this tool to screen for promising prophylactic and therapeutic candidates. An intermediate animal model is needed to confirm any findings from mice studies before testing in the gold-standard non-human primate （NHP） model. In this study, we serially passaged the clinical isolate of MARV/Ang in the livers and spleens of guinea pigs until a variant emerged that causes 100% lethality in guinea pigs （MARV/Ang- GA）. Animals infected with MARV/Ang-GA showed signs of filovirus infection including lymphocytopenia, thrombocytopenia, and high viremia leading to spread to major organs, including the liver, spleen, lungs, and kidneys. The MARV/Ang-GA guinea pigs died between 7-9 days after infection, and the LD50 was calculated to be 1.1x10-1 TCID50 （median tissue culture infective dose）. Mutations in MARV/Ang-GA were identified and compared to sequences of known rodent-adapted MARV/Ang variants, which may benefit future studies characterizing important host adaptation sites in the MARV/Ang viral genome.

Graphite recycling from spent lithium-ion batteries for fabrication of high-performance aluminum-ion batteries

Efficient extraction of electrode components from recycled lithium-ion batteries(LIBs)and their highvalue applications are critical for the sustainable and ecofriendly utilization of resources.This work demonstrates a novel approach to stripping graphite anodes embedded with Li^(+)from spent LIBs directly in anhydrous ethanol which can be utilized as high efficiency cathodes for aluminum-ion batteries(AIBs).Recycled graphite(RG)with foam morphology and crystal structure defects was obtained under the action of ultrasonic peeling and gas generation reaction between residual lithium-graphite interlayer compound and ethanol.The inherent open structure of RG facilitates the intercalation/deintercalation of chloralum anions(AlCl_(4)^(-))and enhances its AIB cathode performance.The electrochemical measurements revea that the RG cathode has a specific capacity of 123 m Ah·g^(-1)at a current of 5 A·g^(-1),which is 1.55 times higher than tha of unprocessed natural graphite and 1.25 times higher than that of commercial artificial graphite.Additionally,the RG cathode demonstrated remarkable stability,retaining its high particular capacity of 138.15 mAh·g^(-1)even through2000 times at 10 A·g^(-1)in a low-cost electrolyte consisting of an ionic liquid/urea/AlCl_(3)mixture.This work offers a novel approach to reusing of graphite anode waste materials from LIBs.

Erratum to:Forecasts on CMB lensing observations with AliCPT-1

One of the authors regrets that there was an omission of affiliation in this published article[1].The affiliation information of author Yi-WenWu only included the institution name for the author,and it is advised to add the university as the author’s second affiliation,which is the 16th affiliation of this article.

Forecasts on CMB lensing observations with AliCPT-1

Ali CPT-1 is the first Chinese cosmic microwave background(CMB) experiment aiming for the high-precision measurement of CMB B-mode polarization. The telescope, currently under deployment in Tibet, will observe in two frequency bands centered at 90 and 150 GHz. We forecast the CMB lensing reconstruction, lensing-galaxy, and lensing-cosmic infrared background(CIB) cross-correlation signal-to-noise ratio(SNR) for Ali CPT-1. We consider two stages with different integrated observation times, namely “4 module*yr”(first stage) and “48 module*yr”(final stage). For lensing reconstruction, we use three different quadratic estimators, namely temperature-only, polarization-only and minimum-variance(MV) estimators, using curved sky geometry. We take into account the impacts of inhomogeneous hit counts and mean-field bias due to incomplete sky coverage.In the first stage, our results show that the 150 GHz channel can measure the lensing signals at 15σ significance with the MV estimator. In the final stage, the measurement significance will increase to 31σ. We also combine the two frequency data in the harmonic domain to optimize the SNR. Our results show that the coadding procedure can significantly reduce the reconstruction bias in the high multiple range. Owning to the high quality of the polarization data in the final stage of Ali CPT-1, the EB estimator will dominate the lensing reconstruction in this stage. We also estimate the SNR of cross-correlations between Ali CPT-1 CMB lensing and other tracers of the large scale structure of the universe. For its cross-correlation with Dark Energy Spectroscopic Instrument(DESI) galaxies/quasars, we report the cross-correlation SNR = 10-20 for the four redshift bins at 0.05 < z < 2.1. In the first stage, the total SNR is approximately 32. In the final stage, the lensing-galaxy cross-correlation can reach SNR = 52. For lensing-CIB cross-correlation, in the first stage, the cross-correlations between Ali CPT-1 lensing and Planck CIB 353, 545 and857 GHz channels are approximately SNR = 18, 19, and 23, respectively. In the final stage, the cross-correlations can reach SNR = 25, 33 and 42. Due to the strong correlations between frequency bands, the total lensing-CIB cross-correlations by combining the three frequencies in Planck CIBs are SNR = 23 and 43 for the Ali CPT-1 first and final stages, respectively.