This study takes Shanghai's restaurants as a case study of urban soft infrastructure, employing big data sets from third-party website platforms for multi-source data fusion, to deeply analyze the impact of urban land expansion and population dynamics on the availability, affordability, acceptability, and accessibility of restaurants. The case study reveals that, despite the Shanghai municipal authorities' focus on mitigating overcrowding in the central urban areas, soft infrastructure such as restaurants in new urban districts remains at a relative disadvantage. The decentralization of soft infrastructure to peripheral urban areas has not met policy expectations, presenting a spatial imbalance characterized by greater provision in the main urban areas than in new urban districts, and higher in Puxi than in Pudong. The single-threshold model uncovers that the positive impact of land urbanization and population dynamics on restaurant convenience undergoes a transformation after reaching a certain critical point, where the linear relationship and synchronous growth shift. By controlling the development area of construction land and the population density within regions, a dynamic combination of availability, affordability, acceptability, and accessibility of restaurants can be achieved. This forms a spatio-temporal management strategy that integrates land, population, and comfort facilities, potentially alleviating the inequity of comfort facilities in Shanghai and the central urban areas' siphoning effect.
Doping in transition metal dichalcogenide (TMD) has received extensive attention for its prospect in the application of photoelectric devices. Currently researchers focus on the doping ability and doping distribution in monolayer TMD and have obtained a series of achievements. Bilayer TMD has more excellent properties compared with monolayer TMD. Moreover, bilayer TMD with different stacking structures presents varying performance due to the difference in interlayer coupling. Herein, this work focuses on doping ability of dopants in different bilayer stacking structures that has not been studied yet. Results of this work show that the doping ability of V atoms in bilayer AA' and AB stacked WS2 is different, and the doping concentration of V atoms in AB stacked WS2 is higher than in AA' stacked WS2 . Moreover, dopants from top and bottom layer can be distinguished by scanning transmission electron microscopy (STEM) image. Density functional theory (DFT) calculation further confirms the doping rule. This study reveals the mechanism of the different doping ability caused by stacking structures in bilayer TMD and lays a foundation for further preparation of controllable-doping bilayer TMD materials.
The density and spatial distribution of substituted dopants affect the transition metal dichalcogenides (TMDCs) materials properties. Previous studies have demonstrated that the density of dopants in TMDCs increases with the amount of doping, and the phenomenon of doping concentration difference between the nucleation center and the edge is observed, but the spatial distribution law of doping atoms has not been carefully studied. Here, it is demonstrated that the spatial distribution of dopants changes at high doping concentrations. The spontaneous formation of an interface with a steep doping concentration change is named concentration phase separation (CPS). The difference in the spatial distribution of dopants on both sides of the interface can be identified by an optical microscope. This is consistent with the results of spectral analysis and microstructure characterization of scanning transmission electron microscope. According to the calculation results of density functional theory, the chemical potential has two relatively stable energies as the doping concentration increases, which leads to the spontaneous formation of CPS. Understanding the abnormal phenomena is important for the design of TMDCs devices. This work has great significance in the establishment and improvement of the doping theory and the design of the doping process for 2D materials.
This study proposes a novel idea of the use of coal gangue (CG) activation and preheated decarburized activated coal CG-based cemented paste backfill material (PCCPB) to realize green mining. PCCPB was prepared with preheated decarburized coal CG (PCG), FA, activator, low-dose cement, and water. This idea realized scale disposal and resource utilization of coal CG solid waste. Decarbonization and activation of CG crushed the material to less than 8 mm by preheated combustion technology at a combustion temperature of 900 °C and a decarbonization activation time of 4 min. The mechanism of the effect of different Na2SO4 dosages on the performance of PCCPB was investigated using comprehensive tests (including mechanical property tests, microscopic tests, and leaching toxicity tests). The results show that the uniaxial compressive strength (UCS) of C-S2, C-S3, and C-S4 can meet the requirements of backfill mining, among which the UCS of C-S3 with a curing time of 3 d and 28 d were 0.545 MPa and 4.312 MPa, respectively. Na2SO4 excites PCCPB at different curing time, and the UCS of PCCPB increases and then decreases with the increase in Na2SO4 dosage, and 3% of Na2SO4 had the best excitation effect on the late strength (28 d) of PCCPB. All groups' (control and CS1-CS4 groups) leachate heavy metal ions met the requirements of groundwater class III standard, and PCCPB had a positive effect on the stabilization/coagulation of heavy metal ions (Mn, Zn, As, Cd, Hg, Pb, Cr, Ba, Se, Mo, and Co). Finally, the microstructure of PCCPB was analyzed using FTIR, TG/DTG, XRD, and SEM. The research is of great significance to promote the resource utilization of coal CG residual carbon and realize the sustainable consumption of coal CG activation on a large scale.
Urban land-use change simulations without considering the sustainable planning policies, especially in special economic park highly concerned by planners, might lack the reliability and availability. Thus, this study proposes a novel planning support systems integrating the Cellular Automata Markov chain model and Shared Socioeconomic Pathways (CA-Markov-SSPs) for predicting the changing of land use and land cover (LULC) at the local and system level by using a novel machine learning-driven, multi-source spatial data modelling framework. Using multi-source satellite data of coastal special economic zones from 2000 to 2020 as a sample, calibration validation based on the kappa indicates a highest average reliability above 0.96 from 2015 to 2020, and the cultivated land and built-up land classes of LULC is the most significant changes in 2030 by using the transition matrix of probabilities, the other classes except water bodies continue to increase. And the non-sustainable development scenario can be prevented by the multiple level collaboration of socio-economic factors. This research intended to help decision makers to confine irrational urban expansion and achieve the sustainable development.
Conservation of Natural Resources , Environmental Monitoring , Reproducibility of Results , Computer Simulation , China , Socioeconomic Factors
To promote the widespread use of fly ash (FA) and coal gasification slag (CGS) in mine filling, reducing the amount of cement and promoting the sustainable development of mining enterprises are essential. In this study, decarbonized CGS (DCGS) was prepared from CGS through decarbonization. A new DCGS-FA filling material was prepared using DCGS, FA, cement (3 wt.%), sodium sulfate (SS), and aeolian sand (AS). The effects of different mass ratios (1/9-5/5) of DCGS/FA on the properties of new filling materials were investigated. The results indicate that CGS can be used with FA to prepare filling materials after decarbonization. The flow performance of the DCGS-FA filling material is positively correlated with the mass ratio of DCGS/FA, while the mechanical properties are negatively correlated. The 28-day unconfined uniaxial compressive strength (UCS) of all specimens met the mechanical requirements (UCS ≥ 1.0 MPa). The types of hydration products were determined through X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The main hydration products of DCGS-FA filling materials are ettringite (AFt) and C-S-H gel. The results of the TG/DTG test of 28 days revealed that an increase in the DCGS/FA mass ratio would reduce the content of hydration products in filling materials. When the mass ratio increased from 1/9 to 5/5, the content of hydration products in the filling material decreased by 54.5%. This study provides a new concept for the resource utilization of CGS and FA in mine filling, which can significantly reduce the amount of cement in filling materials and promote the sustainable development of mine filling.
Coal Ash , Coal , Coal Ash/chemistry , X-Ray Diffraction
With the wide application of the filling mining method, it is necessary to consider the influence of rock activity on the filling body, reflected in the laboratory, that is, the influence of loading rate. Therefore, to explore the response characteristics of loading rate on the mechanical and damage characteristics of aeolian sand paste filling body, DNS100 electronic universal testing machine and DS5-16B acoustic emission (AE) monitoring system were used to monitor the stress-strain changes and AE characteristic parameters changes of aeolian sand paste filling body during uniaxial compression, and the theoretical model of filling sample damage considering loading rate was established based on AE parameters. The experimental results show that: (1) With the increase in loading rate, the uniaxial compressive strength and elastic modulus of aeolian sand paste-like materials (ASPM) specimens are significantly improved. ASPM specimens have ductile failure characteristics, and the failure mode is unidirectional shear failure â tensile failure â bidirectional shear failure. (2) When the loading rate is low, the AE event points of ASPM specimens are more dispersed, and the large energy points are less. At high loading rates, the AE large energy events are more concentrated in the upper part, and the lower part is more distributed. (3) The proportion of the initial active stage is negatively correlated with the loading rate, and the proportion of the active stage is positively correlated with the loading rate. The total number of AE cumulative ringing decreases with the increase in loading rate. (4) Taking time as an intermediate variable, the coupling relationship between ASPM strain considering loading rate and the AE cumulative ringing count is constructed, and the damage and stress coupling model of ASPM specimen considering loading rate is further deduced. Comparing the theoretical model with the experimental results shows that the model can effectively reflect the damage evolution process of ASPM specimens during loading, especially at high loading rates. The research results have significant reference value for subsequent strength design of filling material, selection of laboratory loading rate and quality monitoring, and early warning of filling body in goaf.
The effect of Y2O3 addition on the microstructure and properties of the laser cladded Al-Si alloy coating on the surface of AZ91D magnesium alloy was investigated in this study. The experimental results showed that the Al-Si + Y2O3 cladding layers contained α-Mg, Mg2Si, Al4MgY and a small amount of Al12Mg17 phases. The coarse dendrites, reticulated eutectic structures and massive phases in the coatings tended to be refined and gradually uniformly distributed with the increased amount of Y2O3. The introduction of Y2O3 into the cladding layer favored the improvement of microhardness and wear resistance due to the grain refinement strengthening and dispersion strengthening. The addition of Y2O3 also promoted the reduction of localized corrosion sites and made the corrosion surface smoother, implying that the corrosion resistance of the Y2O3-modified coatings was better than that of the unmodified cladding layer.
BACKGROUND: Nitrogen (N), referred to as a "life element", is a macronutrient essential for optimal plant growth and yield production. Amino acid (AA) permease (AAP) genes play pivotal roles in root import, long-distance translocation, remobilization of organic amide-N from source organs to sinks, and other environmental stress responses. However, few systematic analyses of AAPs have been reported in Brassica napus so far. RESULTS: In this study, we identified a total of 34 full-length AAP genes representing eight subgroups (AAP1-8) from the allotetraploid rapeseed genome (AnAnCnCn, 2n = 4x = 38). Great differences in the homolog number among the BnaAAP subgroups might indicate their significant differential roles in the growth and development of rapeseed plants. The BnaAAPs were phylogenetically divided into three evolutionary clades, and the members in the same subgroups had similar physiochemical characteristics, gene/protein structures, and conserved AA transport motifs. Darwin's evolutionary analysis suggested that BnaAAPs were subjected to strong purifying selection pressure. Cis-element analysis showed potential differential transcriptional regulation of AAPs between the model Arabidopsis and B. napus. Differential expression of BnaAAPs under nitrate limitation, ammonium excess, phosphate shortage, boron deficiency, cadmium toxicity, and salt stress conditions indicated their potential involvement in diverse nutrient stress responses. CONCLUSIONS: The genome-wide identification of BnaAAPs will provide a comprehensive insight into their family evolution and AAP-mediated AA transport under diverse abiotic stresses. The molecular characterization of core AAPs can provide elite gene resources and contribute to the genetic improvement of crop stress resistance through the modulation of AA transport.
Amino Acid Transport Systems/genetics , Brassica napus/enzymology , Gene Expression Regulation, Plant , Stress, Physiological , Amino Acid Transport Systems/metabolism , Brassica napus/genetics , Genome-Wide Association Study , Phylogeny
Long non-coding RNAs (lncRNAs) have been suggested to serve important roles in the development of a number of human cancer types. An increasing amount of data has indicated that the lncRNA small ubiquitin-like modifier 1 (SUMO1) pseudogene 3 (SUMO1P3) has been involved in various types of human cancer. However, the function SUMO1P3 in the development of pancreatic cancer remains unclear. Firstly, reverse transcription-quantitative polymerase chain reaction was performed to determine the expression of SUMO1P3 in pancreatic cancer tissues and cell lines. Then, cell counting kit-8, wound-healing and transwell assays were conducted to explore the effect of SUMO1P3 on pancreatic cancer cell proliferation, migration and invasion. Finally, the EMT-associated proteins were evaluated by western blotting. The results of the present study revealed that SUMO1P3 expression was elevated in pancreatic tissues compared with the corresponding adjacent normal tissues. Additionally, the data indicated that the increased expression of SUMO1P3 is significantly associated with tumor progression and the poor survival of patients with pancreatic cancer. Furthermore, the present study identified that SUMO1P3 knockdown may suppress the proliferation, migration and invasion of pancreatic cancer cells. Additionally, downregulation of SUMO1P3 suppressed the epithelial-mesenchymal transition (EMT) and increased the expression of epithelial cadherin, and decreased the expression of neuronal cadherin, vimentin and ß-catenin. Taken together, the results of the present study demonstrated that SUMO1P3 may participate in EMT and pancreatic cancer progression, thus suggesting that it may be a novel diagnostic and therapeutic biological target for pancreatic cancer.
Long non-coding RNAs (lncRNAs) have been suggested to play important roles in the development of numerous kinds of human cancers. Increasing data has indicated that lncRNA RNCR3 has been involved in some human diseases. However, the exactly biological function and potential mechanisms of RNCR3 in the development of prostate cancer is still unclear. Here, our results confirmed that the RNCR3 expression was increased in prostate cancer compared to the corresponding adjacent normal prostate tissues. Moreover, our data showed that the increased expression of RNCR3 is significantly associated with tumor progression and poor survival of prostate cancer patients. Additionally, we found that RNCR3 knockdown could suppress the ability of proliferation, colony formation, and invasion of prostate cancer cells. Finally, we further confirmed that RNCR3 binds to miR-185-5p, which has been identified as a tumor suppressor in some human cancers, including prostate cancer. We also confirmed that the oncogenic function of RNCR3 in prostate cancer are partly mediated by negative regulation of miR-185-5p targeted BRD8 ISO2. Our data revealed that RNCR3 functions as an tumor-promoting lncRNA in prostate cancer and may serve as a novel important biomarker for the diagnosis and treatment of prostate cancer.
Serpins are ubiquitously distributed serine protease inhibitors that covalently bind to target proteases to exert their activities. Serpins regulate a wide range of activities, particularly those in which protease-mediated cascades are active. The Drosophila melanogaster serpin Spn43Ac negatively controls the Toll pathway that is activated in response to fungal infection. The entomopathogenic fungus Beauveria bassiana offers an environmentally friendly alternative to chemical pesticides for insect control. However, the use of mycoinsecticides remains limited in part due to issues of efficacy (low virulence) and the recalcitrance of the targets (due to strong immune responses). Since Spn43Ac acts to inhibit Toll-mediated activation of defense responses, we explored the feasibility of a new strategy to engineer entomopathogenic fungi with increased virulence by expression of Spn43Ac in the fungus. Compared to the 50% lethal dose (LD50) for the wild-type parent, the LD50 of B. bassiana expressing Spn43Ac (strain Bb::S43Ac-1) was reduced ~3-fold, and the median lethal time against the greater wax moth (Galleria mellonella) was decreased by ~24%, with the more rapid proliferation of hyphal bodies being seen in the host hemolymph. In vitro and in vivo assays showed inhibition of phenoloxidase (PO) activation in the presence of Spn43Ac, with Spn43Ac-mediated suppression of activation by chymotrypsin, trypsin, laminarin, and lipopolysaccharide occurring in the following order: chymotrypsin and trypsin>laminarin>lipopolysaccharide. Expression of Spn43Ac had no effect on the activity of the endogenous B. bassianaderived cuticle-degrading protease (CDEP-1). These results expand our understanding of Spn43Ac function and confirm that suppression of insect immune system defenses represents a feasible approach to engineering entomopathogenic fungi for greater efficacy.
Beauveria/genetics , Beauveria/pathogenicity , Drosophila Proteins/genetics , Moths/microbiology , Pest Control, Biological/methods , Serpins/genetics , Animals , Beauveria/physiology , Drosophila Proteins/metabolism , Drosophila Proteins/toxicity , Genetic Engineering , Hemolymph/immunology , Hemolymph/microbiology , Moths/immunology , Serpins/metabolism , Serpins/toxicity , Virulence
This study aims to investigate the roles of ghrelin signaling in human gastric carcinoma cell lines AGS and SGC7901. Effects of ghrelin signaling on CDK6, P53, NF-κB/P65 and MMP2 mRNA and/or protein expression were determined by real-time PCR and western blot. MTT method and flow cytometry were performed to assess the gastric cancer cell proliferation. The SGC7901 cells overexpressing ghrelin were inoculated into nude mice to produce tumors which were measured later. The wound-healing assay and cell invasion assay were used to test the cell migration and invasive ability of gastric cancer. Ghrelin signaling promotes the oncogene CDK6 gene expression and represses the tumor suppressor gene P53 gene expression in gastric cancer. Ghrelin activates NF-κB/P65 signaling pathway through GHS-R in gastric cancer. Ghrelin upregulates the metastasis factor MMP2 expression via GHS-R/NF-κB signaling pathway in gastric cancer cells and promotes tumor cells migration and invasion, suggesting that ghrelin signaling is a critical pathway in cancer metastasis. Ghrelin induces cell proliferation, migration and invasion via GHS-R/NF-κB signaling pathway in gastric cancer cells. Ghrelin treatment must be avoided for gastric cancer patients.
Cell Movement/drug effects , Ghrelin/pharmacology , NF-kappa B/metabolism , Receptors, Ghrelin/metabolism , Signal Transduction/drug effects , Stomach Neoplasms/pathology , Animals , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lysine/pharmacology , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 2/metabolism , Mice , Neoplasm Invasiveness , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Ghrelin/genetics , Stomach Neoplasms/genetics
