Declined fitness in larvae born from long-distance migrants of anadromous Coilia nasus in the lower reaches of the Yangtze River,China

DEAR EDITOR,Anadromous Coilia nasus is a socioeconomically important species from the middle and lower reaches of the Yangtze River,China.Here,we compared growth and feeding of C.nasus larvae in four reaches along the full migration corridor of the river(640 km)to determine how fitness varies between progenies of short-and long-distance migrants.Results demonstrated that larvae collected in downstream sections grew faster,exhibited higher feeding intensities.

E-beam irradiation of poly(vinylidene fluoride-trifluoroethylene)induces high dielectric constant and all-trans conformation for highly ionic conductive solid-state electrolytes

Polymer matrices have limited abilities to dissociate lithium salts and transport ions,thus making most solid-state polymer electrolytes(SPEs)have extremely low ionic conductivities(10−7-10−5 S/cm)at 25℃.In this work,a high-energy electron-beam(e-beam)irradiation is applied to a poly(vinylidene fluoride-trifluoroethy-lene)[P(VDF-TrFE)]SPE to improve the ionic conductivity.P(VDF-TrFE)easily shows pure all-trans(TTTT)conformation with all fluorine atoms located on one side of the carbon chain to provide an ion transport high-way.E-beam irradiation keeps large amounts of TTTT conformation of P(VDF-TrFE)and produces-CF3 side groups,where the latter expands the interchain distance to split the large ferroelectric domains into nanosize to induce a unique relaxor ferroelectric behavior.This enhances the dielectric constant of the irradiated P(VDF-TrFE)from 15 to 20 and thus facilitates lithium salt dissociation.As a consequence,the ionic conduc-tivity of the irradiated P(VDF-TrFE)SPE is increased from 5.8×10^(−5)to 1.6×10^(−4)S cm^(−1)at 25℃.The solid-state Li//Li symmetrical cell cycles for more than 3000 h at 25℃without a short circuit.Furthermore,the solid-state LFP//Li cell cycles stably for more than 350 cycles with a capacity retention of around 91.3%at 1 C and 25℃.This study paves a new way to prepare high-performance SPEs by inducing high dielectric constants and abundant TTTT conformations through e-beam irradiation.

One-step modification method of a superhydrophobic surface for excellent antibacterial capability

In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorption properties of polydopamine(PDA).We investigate the effect of soaking time from the“one-step method”on the reduction of nano-Ag,surface wettability,and antibacterial properties.Scanning electron microscopy is performed to analyze the distribution of nano-Ag on the surface,whereas X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy are used to analyze the crystal structures and chemical compositions of different surfaces.Samples deposited with PDA on their surface are soaked in a 1H,1H,2H,2H-perfluorodecyltriethoxysilane water–alcohol solution containing AgNO3 for 3 h.Subsequently,a“one-step method”is used to prepare low-adhesion superhydrophobic surfaces containing AgNPs.As immersion progresses,more AgNPs are deposited onto the surface.Compared with the polished surface,the samples prepared via the“one-step method”show significant antibacterial properties against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus.The antibacterial properties of the surface improve as immersion progresses.

Effects of Coptidis Rhizoma on Cell Cycle, DNA Damage, and Apoptosis in L929 Murine Fibroblast Cells

Objective Coptidis Rhizoma （CR）, a widely used traditional Chinese herbal medicine, is commonly believed to be non-toxic. However, little is known about its cytotoxicity and relevant mechanisms at cellular and genetic levels. The present study was conducted to explore the cytotoxicity of CR and its mechanisms related to cell cycle arrest, DNA damage, cell apoptosis, and mitochondrial membrane potential in L929 murine fibroblast cells. Methods The cells were cultured and treated with different concentration of CR aqueous extract for 24 h. Cell viability was determined by CCK-8 method, morphological changes, and mitochondrial membrane potential were observed with an inverted microscope, cell cycle and cell apoptosis were examined by flow cytometry and DNA damages were detected by comet assay. Results Our results showed that cell viability was significantly decreased in a dose-dependent manner when concentration was higher than 0.2 mg/mL. A concentration above 1 mg/mL altered the cells morphology. Each DNA damage indicator score increased in the groups with the concentration of above 0.1 mg/mL. Cells at G2/M phase, cell apoptosis and mitochondrial membrane potential changed in the 2 mg/mL group. Conclusion Overall, our study suggests that CR at a high dosage exhibits cytotoxicity on L929 cells, which is likely to be the consequences of cell cycle arrest, DNA damage, cell apoptosis and mitochondrial membrane potential reduction.