Spatial pattern of urban-rural integration in China and the impact of geography

Urban-rural integration (URI) is a global challenge that is highly related to inequalities, poverty, economic growth, and other Sustainable Development Goals (SDGs). Existing research has evaluated the extent of URI and explored its influencing factors, but urban-rural linkages are seldom incorporated in evaluation systems, and geographical factors are rarely recognized as the influencing factors. We construct a URI framework including regional economy, rural development, urban-rural linkage, and urban-rural gap. Based on a dataset consisting of 1,669 counties in China in 2020, we reveal the spatial pattern of URI and find a high correlation between the spatial pattern of URI and the relief degree of land surface (RDLS). Using structural equation modeling, we discover that topography has direct ( − 0.18, p < 0.001) and indirect ( − 0.17, p < 0.001) effects on URI. The indirect negative effects are mediated through the infrastructure, and the combination of localized advantages and modern technical conditions could mitigate the negative impact of topography. Finally, we identify 742 counties as lagging regions in URI, which can be clustered into eight types. Our findings could facilitate policy designing for those countries striving for integrated and sustainable development of urban and rural areas.

A molecular toolkit to boost functional genomic studies in transformation-recalcitrant vegetable legumes

Dear Editor Legumes,the second-largest family of crops,contribute over one-third of human dietary proteins.Soybean(Glycine max L.),common bean(Phaseolus vulgaris L.),pea(Pisum sativum L.),and cowpea(Vigna unguiculata L.)are among the most widely culti-vated crop legumes for grain and vegetable and are essential for food security globally.

A Bright Nitrogen-doped-Carbon-Dots based Fluorescent Biosensor for Selective Detection of Copper Ions

In this work,a novel fluorescent biosensor has been constructed for rapid detection of Cu(Ⅱ)via the interaction between the fluorophore groups on the surface of nitrogen-doped-carbon-dots(N-CDs)and·OH produced from the catalytic reaction between Cu(Ⅱ)and cysteine(Cys).Specifically,Cu(Ⅱ)can catalyze the oxidation of Cys to form cystine(Cys–Cys)and hydrogen peroxide(H_(2)O_(2)),and Cu(Ⅱ)can also catalyze the decomposition of H_(2)O_(2)to produce hydroxyl radicals(·OH)by the Fenton-like reaction.·OH can oxidize and destroy the surface structure of N-CDs,resulting in the fluorescence quenching of the N-CDs.Under the optimal experimental conditions,the linear range of Cu(Ⅱ)is determined to be 0.05–25μmol L_(-1,),and the limit of detection is 23 nmol L^(-1)with the limit of quantitation of 77 nmol L^(-1).Besides,some characterizations are provided to verify the proposed principle.The method has been successfully applied for the detection of Cu(Ⅱ)in human serum and environmental water with high sensitivity and higher selectivity.

Multifunctional nano-herb based on tumor microenvironment for enhanced tumor therapy of gambogic acid

Multifunctional drug delivery systems(DDSs)have shown great prospects in overcoming the heterogeneous barrier of delivery drugs to the complex tumor microenvironment(TME).In this study,multifunctional AS/Ge-pNAB microgels with dual-active targeting,triple environment responsiveness,and fluorescence imaging capability were prepared through a straightforward procedure.This was aimed to improve the antitumor therapeutic application of gambogic acid(GA)based on the biological characteristics of TME.The microgels have a uniform double-layer structure with aptamer in the outer layer which helps in recognizing receptors on the tumor cells.The GA loaded nano-herb exhibited environment-responsive drug release profiles under acidic pH,reductant and high temperature.The nano-herb significantly improved the accumulation of GA in tumor sites through the synergistic combination of the enhanced permeability and retention effect and dual-ligand mediated internalization.Then,it accelerated intracellular drug release and killed tumor cells.Therefore,the nano-herb had specific therapeutic effects on the tumor in vitro and in vivo as they remarkably inhibited tumor growth while depicting optimal biosafety and lower levels of off-target toxicity.Overall,these findings demonstrate the great potential of the multifunctional AS/Ge-pNAB microgels for precisely targeted GA delivery and open a new avenue for the facile preparation of multifunctional DDSs.