Study on function evolution and coupling coordination degree of "Three Lives Space" in the upper reaches of Yangtze River in China.

Analyzing the functional evolution characteristics and coupling coordination of the "Three Lives Space" in the upper reaches of Yangtze River (URYR) is crucial for achieving high-quality, coordinated development and ecological protection in the region. Based on the panel data of the production function, living function, and ecological function of 31 cities in the URYR from 2010 to 2020, this study establishes the evaluation index system of the "Three Lives Space" function and analyzes its spatio-temporal evolution characteristics and spatial correlation by utilizing the coupling coordination degree model and spatial autocorrelation test. The results indicate that (1) the functional coupling coordination of 31 cities in the URYR exhibits a steady upward trend as a whole, which can be characterized by a sequence of stages, including the disordering decline in disorder, barely coordination, primary coordination, and intermediate coordination. (2) The 31 cities in the URYR have significant spatial agglomeration characteristics. Among them, most cities in Sichuan Province and Chongqing City have high-high gathering effects, and most cities in Guizhou Province and Yunnan Province have low-low gathering effects. Therefore, it is imperative to scientifically and rationally organize the production, living, and ecological space, collectively safeguard the crucial ecological barrier of the URYR, and promote its integrated development.

Impact of digital finance on urban ecological resilience: evidence from the Yangtze River Economic Belt in China.

From the emergence of the new coronavirus pandemic to extreme climatic catastrophes, the development and enhancement of urban ecological resilience has evolved into a critical and strategic imperative. Investigating the capacity of digital finance to promote urban ecological resilience bears substantial relevance to the sustainable advancement of urban centers. This study examines the influence of digital finance on urban ecological resilience by applying a benchmark regression model on data from 107 prefecture-level cities within the Yangtze River Economic Belt across 2011-2020. Additionally, this study delves into its mechanism and spatial spillover impacts via a mediating effect model and a spatial effect model. The findings revealed that (1) digital finance strengthens the ecological resilience of the locale and beneficially impacts the surrounding regions; (2) digital finance enhances urban ecological resilience by fostering technological innovation and reducing energy intensity; and (3) in the lower reaches of the Yangtze River, digital finance plays a greater role in improving urban ecological resilience. Cities with high level of traditional financial development, high level of economic development and high intensity of environmental regulation have a more obvious role in promoting urban ecological resilience. Within the paradigm of ecological civilization, it is advisable for governmental bodies to fortify inter-regional digital financial collaboration, refine the green financial infrastructure, and advocate for sustainable, low-carbon, high-quality urban development.

Correlation Between Increase of Axial Length and Height Growth in Chinese School-Age Children.

PURPOSE: To identify the relationship between the increase in axial length (AL) and height in school-age children and explore the influence of refractive status on such a relationship. METHODS: In this 5-year cohort study, 414 Chinese children (237 boys) aged 6-9 years (mean 7.12) underwent measurements annually. AL was measured using the Lenstar; height with the children standing, without shoes; and refraction using subjective refraction without cycloplegia. Participants were divided according to the refractive status: persistent emmetropia, persistent myopia, and newly developed myopia. The measurement time points of the persistent emmetropia and persistent myopia groups were marked as T1, T2, T3, T4, and T5. The time of myopia onset in the newly developed myopia group was marked as t 0; the preceding time points were marked as t -1, t -2, and so on, and the succeeding as t 1, t 2, and so on. The association between increase in AL and height was analyzed using simple correlation analysis. RESULTS: The mean changes in AL, height, and refraction were 1.39 mm, 23.60 cm, and -1.69 D, respectively, over 5 years in all children. The increase in AL and height were positively correlated for T1~T2, T1~T3, T1~T4, and T1~T5 (r = 0.262, P < 0.001; r = 0.108, P = 0.034; r = 0.165, P = 0.001; r = 0.174, P = 0.001, respectively). The changes in AL and height in the newly developed myopia group were significantly correlated (r = 0.289, P = 0.009) after myopia onset (t 0~t 2). CONCLUSION: The increase in AL and height were positively correlated, especially in the newly developed myopia group after myopia onset. Thus, when children grow quickly, AL elongation should be monitored.

Selective determination of Ag+ in the presence of Cd2+, Hg2+ and Cu2+ based on their different interactions with gold nanoclusters.

In this work, a fluorescence method was developed for selective detection of Ag+ in the presence of Cd2+, Hg2+, and Cu2+ based on gold nanoclusters (AuNCs). That is, bovine serum albumin (BSA) templated AuNCs with double emission peaks were synthesized using BSA as a protective agent. AuNCs with uniform distribution and average size between 2.0 and 2.2 nm were synthesized using a green and simple method, and showed bright orange-red fluorescence under ultraviolet light. AuNCs have two emission peaks at 450 nm and 630 nm with an excitation wavelength of 365 nm. Under alkaline conditions, Cd2+ can combine with the surface sulfhydryl groups of BSA-AuNCs to form Cd-S bonds, which cause AuNCs to aggregate, resulting in an increase in fluorescence intensity at 630 nm. Conversely, due to the d10-d10 metal affinity interaction, the addition of Hg2+ can reduce the fluorescence peak at 630 nm. Ag+ was reduced to Ag0 by gold nuclei in AuNCs, forming a stable hybrid Au@ AgNCs species with blue-shifted and enhanced fluorescence. Finally, the paramagnetic behavior of Cu2+ combined with BSA causes the excited electrons of the gold cluster to lose their energy via ISC, eventually leading to simultaneous quenching of the two emission peaks. The results show that the limit of detection (LOD) of Ag+, Hg2+, Cd2+ and Cu2+ is 1.19 µM, 3.39 µM, 1.83 µM and 5.95 µM, respectively.

Fluorometric sensing of pH values using green-emitting black phosphorus quantum dots.

A fluorometric method is described for "turn-on" sensing of pH values via black phosphorus quantum dots (BPQD). Water-stable BPQD were synthesized by a liquid exfoliation method and characterized by TEM, FT-IR, XPS, and absorption and fluorescence spectra. The nanoparticles of BPQD have a uniform distribution with an average size of 5.2 nm. They exhibit bright green fluorescence, with excitation/emission maxima at 420/515 nm. The fluorescence of the BPQD is likely to arise from the quasi-molecular fluorophores of polycyclic aromatic compounds carrying P-P, P-O-P, and PxOy functions on its surface. The protonation and deprotonation of hydroxyl groups of BPQD causes a different degree of quenching of the BPQD. At pH values below 4.0, protons bind to BPQD to form non-fluorescent ground state complexes. At pH values above 4.0, the hydroxyl groups become deprotonated, and this induces the recovery of fluorescence. The sensor has a linear response in the pH range of 1.0-9.0. It was successfully applied to the determination of the pH values in human urine and serum samples. Graphical abstract Schematic representation of the preparation of black phosphorus quantum dots (BPQDs) from powdered BP crystals using liquid-phase exfoliation in N-methyl-2-pyrrolidone solution. The BPQDs display green fluorescence at high pH values but no fluorescence at very low pH values.

Synthesis of N-doped carbon dots and application in vanillin detection based on collisional quenching.

N-doped carbon dots (NCDs) exhibit bright blue emissions and have been used as viable fluorescent probes in the turn-off fluorometric assay for vanillin detection. NCDs were prepared from glucose and tyrosine using a facile and green synthesis process. The one-pot hydrothermal treatment was used without any strong acid or oxidant. The fluorescence of NCDs (with excitation/emission peaks at 323/416 nm, respectively) can be quenched by vanillin. The quenching mechanism belongs to the dynamic quenching mode due to the molecular collisions of the ground state of vanillin and the excited state of NCDs. This turn-off system could be utilized to quantify vanillin within a linear range of 0.43-264 µM. The limit of detection was 0.10 µM. Moreover, this approach was successfully applied toward the determination of vanillin in food samples.

Fluorometric determination of hydroquinone by using blue emitting N/S/P-codoped carbon dots.

N/S/P-codoped carbon dots (CDs) are shown to be a viable fluorescent probe in a turn-off-on fluorometric assay for hydroquinone (HQ). The preparation of CDs was carried out using a one-step hydrothermal reaction starting with glyoxal and isocarbophos. The method is based on the formation of ground state complexes between CD and Fe(III) which leads to quenching of blue fluorescence (with excitation/emission peaks at 363/448 nm). On addition of HQ, it will be oxidized by Fe(III) upon which fluorescence recovers. This turn-off-on system can be utilized to quantify HQ. A linear relationship exists between fluorescence recovery and HQ concentration in range between 0.56 and 375 µM. The limit of detection is 0.16 µM. The assay was successfully applied to the determination of HQ in spiked water samples and developer samples. Graphical abstract Fluorometric determination of hydroquinone (with good selectivity over catechol and resorcinol) by using blue-emitting N/S/P-codoped carbon dots and the quenching effect of Fe(III).

Assay of miRNA in cell samples using enhanced resonance light scattering technique based on self aggregation of magnetic nanoparticles.

AIMS: miRNAs are regarded as potential biomarkers correlated with the development and progression of many diseases. However, it is a challenge to construct a sensitive method to detect them without using time-consuming radioactive labeling or complex amplification strategies. METHODS: A facile resonance light scattering (RLS) system was developed for the detection of miRNA employing magnetic nanoparticles (MNPs) as RLS probes. MNPs were coated with streptavidin. DNA probes were modified on the surface of MNPs based on the specific interaction of streptavidin and biotin forming MNPs@DNA probes. MNPs@DNA probes dispersed in homogeneous media causing low RLS signal. RESULTS & CONCLUSION: miRNA hybridized with DNA probes resulting in the aggregation of MNPs and inducing the enhancement of RLS intensity. miRNAs were determined successfully with limit of detection at 0.9 picomole per liter (pM). The potential clinical application of the present biosensor was also demonstrated by measuring miRNAs in human normal and cancer cells, and human serum samples.

Resonance light scattering aptasensor for urinary 8-hydroxy-2'-deoxyguanosine based on magnetic nanoparticles: a preliminary study of oxidative stress association with air pollution.

An aptamer based method is described for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG) using resonance light scattering (RLS). Magnetic nanoparticles (MNPs) were employed as RLS probes. The probe DNA was placed on the surface of MNPs, which produces a rather low RLS signal. If, however, probe DNA hybridizes with the aptamer against 8-OHdG, a sandwich structure will be formed. This results in a significant enhancement of RLS intensity. The aptamer was used as the recognition element to capture 8-OHdG. 8-OHdG has a stronger affinity for the aptamer than probe DNA, and the conformation of the aptamer therefore switches from a double-stranded to a G-quadruplex structure. As a result, MNPs labeled with probe DNA are released, and RLS intensity decreases. The method allows 8-OHdG to be detected with a linear response in the 32 pM - 12.0 nM concentration range and an 11 pM limit of detection (at 3.29SB/m, according to the recent recommendation of IUPAC). The MNPs can be reused 5 times by applying an external magnetic field for collection. The method was successfully applied to analyze human urine samples for its content of 8-OHdG. It was also found that the levels of 8-OHdG noticeably increased with the increase of the Air Quality Index. Conceivably, the method is a viable tool to investigate the relationship between 8-OHdG levels and the effect of air pollution. Graphical abstract A reusable sensing strategy was constructed to detect urinary 8-OHdG based on "turn-off" resonance light scattering. The LOD was as low as 11 pM. This study showed some preliminary data for the association between oxidative stress and air pollution.

[Research on the variation regularity of effluent from the leachate reverse osmosis concentrate recirculation].

To provide certain theoretical basis for selecting recirculation landfill scientifically and reasonably, the variation regularity of recirculation effluent from the landfill columns in three different years was studied. By using leachate reverse osmosis concentrate from a refuse landfill in Chengdu, the recirculation experiments were carried out in three landfill columns filled with garbage in 1, 5 and 15 landfill ages respectively. The variation regularity of pH, total organic carbon, ammonia nitrogen, nitrate nitrogen and heavy metals of recirculation effluent was researched. It showed that the one-year landfill column with a favorable ability of removing nitrate nitrogen and degradation rate of nitrate nitrogen reaching above 88% was in the stage of producing methanation, but the concentration of organic matter and ammonia nitrogen of the effluent is higher and changes in the parameters mainly depend on the biological function. The five-year landfill column without typical features of mineralized refuse and with relatively poor adsorption capacity and biological effects, as well as removal capacity of organic matter, salinity, Cr and Ni approaches stabilization. The fifteen-year landfill column has high capability of adsorption, complexing, as well as organic matter, salinity, Cr and Ni removal, and the removal rate at the initial stage reaches 90%, 78%, 93% and 78%, respectively, but the recirculation process and progress need to be controlled when the rate approaches or reaches the adsorption capacity.

Enhanced white matter tracts integrity in children with abacus training.

Experts of abacus, who have the skills of abacus-based mental calculation (AMC), are able to manipulate numbers via an imagined abacus in mind and demonstrate extraordinary ability in mental calculation. Behavioral studies indicated that abacus experts utilize visual strategy in solving numerical problems, and fMRI studies confirmed the enhanced involvement of visuospatial-related neural resources in AMC. This study aims to explore the possible changes in brain white matter induced by long-term training of AMC. Two matched groups participated: the abacus group consisting of 25 children with over 3-year training in abacus calculation and AMC, the controls including 25 children without any abacus experience. We found that the abacus group showed higher average fractional anisotropy (FA) in whole-brain fiber tracts, and the regions with increased FA were found in corpus callosum, left occipitotemporal junction and right premotor projection. No regions, however, showed decreased FA in the abacus group. Further analysis revealed that the differences in FA values were mainly driven by the alternation of radial rather than axial diffusivities. Furthermore, in forward digit and letter memory span tests, AMC group showed larger digit/letter memory spans. Interestingly, individual differences in white matter tracts were found positively correlated with the memory spans, indicating that the widespread increase of FA in the abacus group result possibly from the AMC training. In conclusion, our findings suggested that long-term AMC training from an early age may improve the memory capacity and enhance the integrity in white matter tracts related to motor and visuospatial processes.