Ethanolic extract of propolis induces apoptosis of HL-60 cells in vitro

Objective The aim of the study was to investigate whether ethanolic extract of propolis inhibits the growth and induces apoptosis of HL-60 cel s. Methods HL-60 cel s were treated for 24, 48, 72 h with various concentrations ethanolic extracts of prop-olis （0, 50, 100, and 200 μg/mL）. The proliferation of HL-60 cels was determined using the 3-（4,5-dimeth-ylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. Subsequently, Hochest 33258 staining and terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） were used to test the apoptosis of HL-60 cel s. We observed the expression levels of Bax and Bcl-2 in HL-60 cel s by immunohistochemistry. Results MTT assay showed that various concentrations of ethanolic extract of propolis had significant inhibitory efect on HL-60 cel proliferation （P〈 0.05）. Typical morphologic changes could be observed by fluorescence microscope and TUNEL. By immunohistochemistry, we found the expression level of Bax was up-regulated, whereas that of Bc1-2 was down-regulated （P 〈 0.05）.Conclusion Ethanolic extract of propolis inhibits leukemia cel proliferation and induces apoptosis in vitro. Its mechanism may be related to the regulation of Bax and Bcl-2 expression and up-regulation of Bcl-2/Bax ratio.

Anthocyanins/chitosan films doped by nano zinc oxide for active and intelligent packaging:comparison of anthocyanins source from purple tomato or black wolfberry

The multifunctional films was prepared by blending chitosan and nano-ZnO with purple tomato anthocyanins or black wolfberry anthocyanins.The properties of films functioned by anthocyanins source and nano-ZnO content were studied.It was found purple tomato anthocyanins showed more significant color change against pH than black wolfberry anthocyanins.The nano-ZnO were widely dispersed in matrix and enhanced the compatibility of anthocyanins with chitosan.However,the anthocyanins source influenced the properties of the films more slightly than nano-ZnO addition.The tensile strength,antioxidant and antibacterial effects of the chitosan films dramatically increased after cooperated by nano-ZnO and anthocyanins,which also enhanced with increase of nano-ZnO content,whereas the elongation at break of the composite films decreased.Especially,the anthocyanin and nano-ZnO promoted the antibacterial activity of films synergistically.Composite films made from black wolfberry anthocyanins exhibited higher mechanical performance than those made from purple tomato anthocyanins but weaker antibacterial effects.The purple tomato anthocyanins/chitosan and nano-ZnO/purple tomato anthocyanins/chitosan films effectively reflected pork spoilage,changing their colors from dark green to brown,indicating the potential for applications in active and intelligent food packaging.

Uncertainty in projections of the South Asian summer monsoon under global warming by CMIP6 models:Role of tropospheric meridional thermal contrast

Driven by the increase in CO_(2)concentration,climate models reach a consensus that the large-scale circulation of the South Asian summer monsoon(SASM) becomes weakened but with different magnitudes.This study investigates the major uncertainty sources of the SASM response to an abrupt quadrupling of CO_(2)(abrupt-4×CO_(2))in 18 models of phase 6 of the Coupled Model Intercomparison Project.The projected weakening of the SASM indicated by both zonal and meridional monsoon circulation indices is closely linked to decreases in the meridional gradient of upper-tropospheric temperature between Eurasia and the Indian Ocean(EUTT-IUTT).A climate feedback-response analysis method is applied to linearly decompose the uncertainty of changes in EUTT-IUTT into the partial changes due to external forcing and internal processes of the earth-atmosphere column.Results show that the uncertainty of changes in EUTT-IUTT is contributed positively by the dominant atmospheric dynamic process,followed by the cloud shortwave radiative effect,and negatively by the surface latent heat flux and cloud longwave radiative effect.Contributions from CO_(2)forcing and other internal processes including albedo and water vapor feedbacks,oceanic heat storage,and sensible heat flux are found to be minor.

Tropical Stratospheric Forcings Weaken the Response of the East Asian Winter Temperature to ENSO

The El Niño-Southern Oscillation(ENSO)plays a critical role in predicting the winter surface temperature over East Asia.Numerous studies have attempted to improve the seasonal forecasting skill in view of the combined effects of ENSO and oceanic-tropospheric factors.However,high uncertainty and notable challenges still exist in using the ENSO to predict the surface temperature.Here,we showed that tropical stratospheric forcings(Quasi-Biennial Oscillation,QBO)could disrupt the response of the surface temperature to ENSO.The response of the East Asian surface temperature to El Niño/La Niña events evidently weakened in winter during the westerly/easterly phase of the QBO.This disruption has shown an increasing trend in recent decades,limiting the usefulness of ENSO alone as a seasonal predictor of the surface temperature.The modulation of the QBO on the East Asian surface temperature is achieved mainly by affecting subtropical zonal winds and North Pacific wave activity.Our analyses suggest that the QBO is a nonnegligible predictor in improving seasonal forecasts of the East Asian surface temperature,even comparable to the ENSO.

Monodisperse Fe3O4 spheres: Large-scale controlled synthesis in the absence of surfactants and chemical kinetic process

Fe3 O4 has attracted tremendous interest in vast areas of biomedicine and catalysis as well as environment engineering.However,it is highly desired to fully understand the chemical kinetic process and propose a general,surfactantfree,large-scale synthesis approach for Fe3 O4 spheres.Herein,we developed a facile scalable solvothermal method in the absence of surfactants to produce Fe3 O4 spheres with the yield of 5.1 g,which present tunable sizes from 107 to 450 nm by modulated molar ratio of Fe3+/COO-in the solution.Particularly,it is observed that the reactants undergo a redox process,composed of a precipitation-dissolution equilibrium combined with a coordination reaction(termed as RPC),to the final product based on the LaMer model.It is worth noting that the generation of di-carboxyl group and its coordination with iron cations determine the formation of Fe3 O4 spheres.This work not only offers a strategy to precisely tailor the particle size in scalable synthesis process,but also gives the insight on the role of dihydric alcohol in the formation mechanism of Fe3 O4 spheres in the absence of surfactants.

Single-cell RNA Sequencing Reveals Sexually Dimorphic Transcriptome and Type 2 Diabetes Genes in Mouse Islet β Cells

Type 2 diabetes(T2D)is characterized by the malfunction of pancreaticβcells.Susceptibility and pathogenesis of T2D can be affected by multiple factors,including sex differences.However,the mechanisms underlying sex differences in T2D susceptibility and pathogenesis remain unclear.Using single-cell RNA sequencing(scRNA-seq),we demonstrate the presence of sexually dimorphic transcriptomes in mouseβcells.Using a high-fat diet-induced T2D mouse model,we identified sex-dependent T2D altered genes,suggesting sex-based differences in the pathological mechanisms of T2D.Furthermore,based on islet transplantation experiments,we found that compared to mice with sexmatched islet transplants,sex-mismatched islet transplants in healthy mice showed down-regulation of genes involved in the longevity regulating pathway ofβcells.Moreover,the diabetic mice with sex-mismatched islet transplants showed impaired glucose tolerance.These data suggest sexual dimorphism in T2D pathogenicity,indicating that sex should be considered when treating T2D.We hope that our findings could provide new insights for the development of precision medicine in T2D.