Spatial Distribution and Influencing Factors of Urban Shrinkage from the Perspective of Factor Flow - A Case Study of National Urban Agglomerations

This paper examines national urban agglomerations by taking factor flows as the focal point as the research subject.By dividing the stages of urban agglomeration development,a comprehensive framework of urban shrinkage is constructed,encompassing economic,population,and social shrinkage.The study explores the spatial distribution characteristics of urban shrinkage during different stages of urban agglomeration and investigates the influencing factors using a geographic detector model.The findings reveal that urban shrinkage within urban agglomerations is widely spread,predominantly in peripheral areas.During the diffusion stage,urban shrinkage is scattered,with population shrinkage concentrated in peripheral regions,economic shrinkage concentrated on old industrial cities,and social shrinkage concentrated on the northeast.The outcomes of the geographic detector model indicate that traffic flow,capital flow,information flow,node importance,network connectivity,government investment,openness,and environmental regulations all play significant roles in shaping the spatial distribution of urban shrinkage.

LncRNA LINC00525 suppresses p21 expression viamRNA decay and triplex-mediated changes in chromatin structure in lung adenocarcinoma

Background:Emerging evidence suggests that long noncoding RNAs(lncRNAs)play crucial roles in various cancers.In the present study,we aim to investigate the function and molecular mechanism of an up-regulated and survivalassociated lncRNA,LINC00525,in lung adenocarcinoma(LUAD).Methods:The expression level of LINC00525 in tissueswas determined by quantitative reverse transcription polymerase chain reaction(RT-qPCR)and in situ hybridization(ISH).The functional role of LINC00525 in LUAD was investigated using gain-and loss-of-function approaches,both in vivo and in vitro.RNA pull-down,RNA immunoprecipitation(RIP),chromatin immunoprecipitation(ChIP),triplex-capture assay,dual-luciferase assay,gene expression microarray,and bioinformatics analysis were used to investigate the potential underlying mechanisms involved.Results:LINC00525 is highly expressed in LUAD cells and tissues.Survival analysis indicated that upregulation of LINC00525 was associated with poor prognosis in patients with LUAD patients.Knockdown of LINC00525 inhibited cell proliferation and cell cycle progression in vitro.In xenograft models,LINC00525 knockdown suppressed tumor growth and tumorigenesis of tumorbearing mice.Mechanistically,LINC00525 epigenetically suppressed p21 transcription by guiding Enhancer Of Zeste 2 Polycomb Repressive Complex 2 Subunit(EZH2)to the p21 promoter through an formation of RNA-DNA triplex with the p21 promoter,leading to increased trimethylation of lysine 27 on histone 3(H3K27me3)of the p21 promoter.In addition,LINC00525 repressed p21 expression post-transcriptionally by enhancing p21mRNA decay.LINC00525 promoted p21mRNAdecay by competitively binding toRNABindingMotif Single Stranded Interacting Protein 2(RBMS2).Conclusion:Our findings demonstrate that LINC00525 promotes the progression of LUAD by reducing the transcription and stability of p21 mRNA in concert with EZH2 and RBMS2,thus suggesting that LINC00525 may be a potential therapeutic target for clinical intervention in LUAD.

Analysis for remedial alternatives of unregulated municipal solid waste landfills leachate-contaminated groundwater

A groundwater flow and solute transport model was developed using Visual Modflow for forecasting contaminant transport and assessing effects of remedial alternatives based on a case study of an unregulated landfill leachate-contaminated groundwater in eastern China. The results showed that arsenic plume was to reach the pumping well in the downstream farmland after eight years, and the longest lateral and longitudinal distance of arsenic plume was to reach 200 m and 260 m, respectively. But the area of high concentration region of arsenic plume was not to obviously increase from eight years to ten years and the plume was to spread to the downstream river and the farmland region after 20 years; while the landfill＇s ground was hardened, the plume was not to reach the downstream farmland region after eight years; when the pumping well was installed in the plume downstream and discharge rate was 200m3/d, the plume was to be effectively restrained; for leakage-proof barriers, it might effectively protect the groundwater of sensitive objects within an extent time range. But for the continuous point source, the plume was still to circle the leakage-proof barrier; when discharge rate of drainage ditches was 170.26 m3/d, the plume was effectively controlled; the comprehensive method combining ground-harden with drainage ditches could get the best effect in controlling contaminant diffusion, and the discharge rate was to be reduced to 111.43 m3/d. Therefore, the comprehensive remedial alternative combining ground-harden with drainage ditch will be recommended for preventing ground-water contamination when leachate leakage has happened in unregulated landfills.

Preparation of nZVI embedded modified mesoporous carbon for catalytic persulfate to degradation of reactive black 5

High-efficiency and cost-effective catalysts with available strategies for persulfate(PS)activation are critical for the complete mineralization of organic contaminants in the environmental remediation and protection fields.A nanoscale zero-valent iron-embedded modified mesoporous carbon(MCNZVI)with a core-shell structure is synthesized using the hydrothermal synthesis method and high-temperature pyrolysis.The results showed that nZVI could be impregnated within mesoporous carbon frameworks with a comparatively high graphitization degree,rich nitrogen doping content,and a large surface area and pore volume.This material was used as a persulfate activator for the oxidation removal of Reactive Black 5(RB5).The effects of the material dosage,PS concentration,pH,and some inorganic anions(i.e.,Cl^(−),SO_(4)^(2−))on RB5 degradation were then investigated.The highest degradation efficiency(97.3%)of RB5 was achieved via PS(20 mmol/L)activation by the MCNZVI(0.5 g/L).The pseudo-first-order kinetics(k=2.11×10^(−2)min^(−1))in the MCNZVI/PS(0.5 g/L,20 mmol/L)was greater than 100 times than that in the MCNZVI and PS.The reactive oxygen species(ROS),including^(1)O_(2),SO_(4)^(·−),HO^(.),and·O_(2)^(−),were generated by PS activation with the MCNZVI.Singlet oxygen was demonstrated to be the primary ROS responsible for the RB5 degradation.The MCNZVI could be reused and regenerated for recycling.This work provides new insights into PS activation to remove organic contamination.