15 research outputs found

    Studying the distribution patterns, dynamics and influencing factors of city functional components by gradient analysis

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    Understanding the spatial distribution characteristics and formation mechanism of urban facilities (city functional components) constitutes the basis of urban layout optimization. Currently, research on the overall distribution of the various types of city functional components is lacking. In this study, by applying the gradient analysis method common in ecology, we considered 13 types of city functional components (80,214 individuals in total) in large, medium and small Chinese cities (9 cities in total) to carry out quantitative analysis of the distribution of components along urban–rural gradients through density distribution curves. The results indicated that: (1) a higher density of city functional components near the city centre revealed an obvious aggregated distribution; (2) the spatial distribution dynamics of city functional components were related to the city size, providing a reference for the rational distribution of components in cities of different sizes; (3) the distribution of city functional components was affected by their ecosystem services. This study offers a new perspective for the application of ecological methods in the examination of the distribution of city functional components

    Efficient catalytic hydrogen generation from formic acid dehydrogenation on ultrafine PdAu nanoparticles supported on modified carbon derived from rice straw

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    Formic acid (FA) dehydrogenation at ambient conditions is a promising route for hydrogen (H2) generation but still suffers from low activity and selectivity. Here, potassium hydroxide (KOH) and 3-aminopropyl triethoxysilane (APTES) modified porous carbon derived from the pyrolysis of rice straw (RSNPC) offers an effective support to promote the formation of ultrafine PdAu nanoparticles (NPs). Benefiting from the small sizes of PdAu NPs, the Pd0.7Au0.3/RSNPC catalyst exhibits excellent catalytic performance for FA dehydrogenation reaction with a high turnover frequency (TOF) of 6794.3 mol H2 mol catalyst−1 h−1 at ambient conditions, outperforming most of reported catalysts for FA dehydrogenation under similar conditions

    Nanococktail Based on Supramolecular Glyco-Assembly for Eradicating Tumors In Vivo

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    The development of robust phototherapeutic strategies for eradicating tumors remains a significant challenge in the transfer of cancer phototherapy to clinical practice. Here, a phototherapeutic nanococktail atovaquone/17-dimethylaminoethylamino-17-demethoxygeldanamycin/glyco-BODIPY (ADB) was developed to enhance photodynamic therapy (PDT) and photothermal therapy (PTT) via alleviation of hypoxia and thermal resistance that was constructed using supramolecular self-assembly of glyco-BODIPY (BODIPY-SS-LAC, BSL-1), hypoxia reliever atovaquone (ATO), and heat shock protein inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG). Benefiting from a glyco-targeting and glutathione (GSH) responsive units BSL-1, ADB can be rapidly taken up by hepatoma cells, furthermore the loaded ATO and 17-DMAG can be released in original form into the cytoplasm. Using in vitro and in vivo results, it was confirmed that ADB enhanced the synergetic PDT and PTT upon irradiation using 685 nm near-infrared light (NIR) under a hypoxic tumor microenvironment where ATO can reduce O2 consumption and 17-DMAG can down-regulate HSP90. Moreover, ADB exhibited good biosafety, and tumor eradication in vivo. Hence, this as-developed phototherapeutic nanococktail overcomes the substantial obstacles encountered by phototherapy in tumor treatment and offers a promising approach for the eradication of tumors. </p

    Water Purification Capacity of the Constructed Wetland to Micro-Pollution Water Source —— a Case Study in Jiaxing

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    Constructed wetlands are commonly applied to improve and maintain water quality of micro-polluted water sources as a feasible and cost-effective technique. However, the purification capacity of the constructed wetland for micro-polluted water was lacking of understanding. This study collected the turbidity, ammonia nitrogen (NH3-N), nitrite nitrogen (NO2-N), total nitrogen (TN), Fe, Mn, total phosphorus (TP), permanganate index (CODMn), dissolved oxygen (DO), and chemical oxygen demand (COD) at the water inlet and outlet of Guanjinggang Wetland in Jiaxing City from 2019 to 2021. The comparisons among the pollution indicators showed that the wetland reduced the pollutions and slowed down the fluctuations of pollution indicators, except for Do, TN and COD. The removal rates are different due to the causes of pollution indicators. The partial regression analysis to different influencing factors showed the water temperature were the main influencing factor to the turbidity, NH3-N, Fe with the partial correlation of 0.447, -0.631, 0.510, respectively. Precipitation showed the highest influence on Mn with the partial correlation of 0.323. Flow showed highest influence on COD with the partial correlation of -0.339. Both flow and water temperature were the highest influence factors on No2-N, CODMn, Do and TN. However, water purification agent was not the main influence factor on any pollution indicators. The research results are conducive to improving the understanding of water security in the Yangtze River Delta region

    RUNX3 Inhibits the Invasion and Metastasis of Human Colon Cancer HT-29 Cells by Upregulating MMP-2/9

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    Objective. To investigate the effect of Runt-associated transcription factor 3 (RUNX3) on the invasion and metastasis of human colon cancer HT-29 cells and to preliminarily explore the mechanism of its anticancer effect. Methods. The RUNX3 plasmid vector was transfected into human colon cancer HT-29 cells by liposome-mediated transfection, while the empty vector and the blank group were used as the control group. After Geneticin (G418) screening, HT-29 cells with stable expression of RUNX3 gene were obtained. The expressions of mRNA and proteins of RUNX3 and metalloproteinases (MMP)-2/9 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Cell proliferation was determined by MTT assay. The effect of RUNX3 on invasion and metastasis of HT-29 cells was evaluated by scratch injury assay, Transwell chamber, and Matrigel invasion model. Results. RUNX3 was expressed stably in HT-29 cells after transfection. The expressions of RUNX3 mRNA and proteins in the experimental group were significantly higher than those in the blank/empty vector groups. Meanwhile, the expressions of MMP-2/9 mRNA and proteins in the observation group were significantly lower than those in the blank group and the empty vector group. The proliferation and migration ability in the experimental group was significantly lower than blank/empty vector groups from the third day. Transwell chamber experiment and Matrigel invasion assay showed that the number of Transwell cells was decreased significantly than blank/empty vector groups, but no difference was found between the blank group and the empty vector group. Conclusion. RUNX3 can inhibit the invasion and metastasis of human colon cancer HT-29 cells, and the mechanism may be related to decreased expression of MMP-2 and MMP-9

    Inequalities of urban green space area and ecosystem services along urban center-edge gradients

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    Rising inequality threatens the improvement of human well-being. As an important type of green infrastructure within cities, urban green spaces provide ecosystem services and contribute to human health. The inequalities of per capita urban green space area and ecosystem services are critical environmental justice and public health issues but are not well understood. Based on the spatial patterns of green spaces, land rent, and the population of 20 cities in China, we assessed the inequalities of per capita green space area and ecosystem services by using the Gini coefficient. Results showed that, (1) the Gini coefficient (an indicator to measure inequality) of per capita available ecosystem services was 0.430, which was greater than that of per capita green space area (0.357), (2) the inequality of per capita ecosystem services had a negative relationship with city size measured by population and GDP, and (3) the inequality of green space area was negatively related to the subjective quality of life, while the inequality of ecosystem services was negatively related to the economic competitiveness of cities. We suggest that urban planners comprehensively consider multiple indicators (such as per capita green space area, Gini coefficients of per capita green space area and ecosystem services) to simultaneously evaluate the efficiency and equality of green space construction
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