Anthropogenic effects on soils in the eastern Tibetan Plateau revealed by geochemical elemental characteristics.

The Tibetan Plateau (TP) constitutes a fragile and sensitive ecological environment, which is vulnerable to global climate change and human activities. To investigate the anthropogenic effects on the TP's environmental system is valuable for guiding human responses and adaptations to future environmental changes. In this study, we detailedly analyzed the geochemical elements of four representative soil sections developed on loess from Ganzi, Jinchuan, Aba, and Chuanzhusi in the eastern TP. The chemical elemental profiles distinctly indicated the presence of typical anthropogenic elements (Cu, Zn, Ni, Cr, Pb, Mn, and Fe), underscoring the substantial influence of human activities on TP soil, and showing spatial variance. Our results indicate that anthropogenic impacts were relatively low at Aba and Ganzi, resulting in a deficit of anthropogenic elements at the surface layer. Whereas at Jinchuan and Chuanzhusi, relatively intense anthropogenic impacts have led to the enrichment of anthropogenic elements in the topsoil. We infer that agricultural activities, increased traffic, and expansion of tourism activities were the major factors affecting the anthropogenic elements of TP soils. Our study highlights the impact of human activities on soil geochemical processes in the Tibetan Plateau.

Cryopreservation of herbaceous Asteraceae seeds: Effects of seed reserves on seed germination and seedling regrowth.

Carbohydrate, lipid and protein, the three main storage reserves of seeds, are the main sources of raw materials and energy for seed germination and early growth stage of seedlings. In this study, the seed of 16 Asteraceae herbaceous ornamentals were used to compare the changes in seed germination, seedling growth indexes and four major storage reserves of seeds before and after cryopreservation. After cryopreservation, seed germination and seedling growth were preserved in most species (11/16), while one species showed significantly improved post-thaw germination and four had decreased germination. In seeds with preserved germination, no clear variation was noted with regards to the four kinds of storage reserves, or only a slight change in one. However, significantly reduced soluble protein, soluble sugar and fat content and increased starch content were detected in seeds showing reduced germination after cryopreservation. The correlation study further showed that the changes in seed germination were positively correlated with soluble protein, soluble sugar and fat, and negatively correlated with starch. In seedling growth indexes, only cotyledon area was correlated to the content of soluble protein, starch, fat, and seed germination after cryopreservation. These results support the use of soluble protein, soluble sugar, starch and fat as indicators of seed germination after cryopreservation, but not for predicting the seedling growth indexes.

A comparative plastomic analysis of Ziziphus jujuba var. spinosa (Bunge) Hu ex H. F. Chow and implication of the origin of Chinese jujube.

Comparative plastomics can be used to explicitly dissect various types of plastome variation. In the present study, the plastome variation pattern of Ziziphus jujuba var. spinosa (also called sour jujube) and its phylogenomic relationship with Chinese jujube were investigated. Plastomes of 21 sour jujube individuals were sequenced and assembled. The length of the sour jujube plastomes ranged between 159399 and 161279 bp. The plastomes exhibited collinearity of structure, gene order and content. The most divergent regions were located in the intergenic spacers, such as trnR-UCU-atpA and psbZ-trnG-UCC. Sliding window analysis demonstrated that the sequence variation among the sour jujube plastomes was relatively low. Sixty-two to 76 SSRs with 4 motif types were identified in the sour jujube plastomes with a predominant motif type of A/T. Three protein-coding genes exhibited higher nonsynonymous/synonymous substitution ratios, indicating that these genes may undergo positive selection. A total of 80 SNPs were detected and 1266 potential RNA editing sites of 23 protein-coding genes were predicted. In the phylogenomic tree constructed, sour jujube has a sister relationship to Chinese jujube, which indicates that Chinese jujube may have originated or been domesticated from sour jujube. The present study explicitly investigated the individual-level plastome variation of sour jujube and provides potential valuable molecular markers for future genetic-related study of this lineage.

Developing an improved UHPLC method for impurity profile analysis of ceftriaxone using analytical quality by design.

In this study, we developed a new reversed-phase ultra-high-performance liquid chromatography (UHPLC) method for comprehensively measuring impurities in ceftriaxone. The method was developed based on the Chinese Pharmacopoeia (ChP) HPLC method, which is limited by the lack of selectivity to potential impurities and a long running time. Screening experiments showed that octylamine concentration, mobile phase pH, and organic phase ratio were critical method parameters. Further optimisation and Monte-Carlo simulations were performed to map out the design space. The selected working conditions resulted in a complete separation of the impurity profile in approximately 10 min. A multivariate approach confirmed that the method was robust, and the proportion of acetonitrile should be carefully controlled. Additionally, the developed UHPLC method could be transferred back to HPLC in a single step using a Columns Calculator, providing a new approach for the rapid and effective development of the HPLC method. Our findings could serve as a reference for developing the next version of the ChP.

Trade-offs and synergistic relationships of ecosystem services under land use change in Xinjiang from 1990 to 2020: A Bayesian network analysis.

Ecosystem service value (ESV) refers to the value of benefits provided by the ecosystem to people, and can reflect the quality of regional ecological environment. There have been few studies on ESV in arid regions experiencing dramatic land use changes. Also, many past ESV studies have obtained distorted results by using a simple linear function to examine the trade-offs between driving factors. This study quantified ESV in Xinjiang from 1990 to 2020 based on value equivalent method. Differences in ESV among ecosystem services in Xinjiang under different scenarios were simulated using a Bayesian network model. The results demonstrated land use changes in Xinjiang from 1990 to 2020, with construction land expanding the most significantly (dynamic index: 224.63 %), whereas grassland area decreased (dynamic index: -1.31 %) due to transformation to unused and cultivated land. ESV in Xinjiang presented an N-shaped variation trend from 1990 to 2020 and decreased by 309.6 × 108 CNY, with a variation rate of -20.35 %. The rank of the four categories of ecological services from 1990 to 2020 in terms of ESV was: regulating services > support services > cultural services > supply services. There was a gradual reduction in ESV in Xinjiang from 1990 to 2020. The rank of the different regions in terms of the reduction in ESV was: Northern Xinjiang (295.24 × 108 CNY) > Southern Xinjiang (280.94 × 108 CNY) > Eastern Xinjiang (109.76 × 108 CNY). Land use change was a direct driver of changes in ESV, whereas natural and social factors, such as precipitation, temperature, population, and policy factors, were indirect drivers. This study can act as a reference for sustainable management of ecosystem services in arid regions.

Heavy Metal Pollution and Risk Assessment of Surface Dust in the Arid NW China.

High concentrations of heavy metals (HMs) in urban surface dust (USD) can be extremely hazardous to urban ecology and human health. Oasis cities are located at the edge of deserts and are more exposed to salt/sandstorms, and they face a significantly higher accumulation of USD than wet or semi-humid areas. However, systematic studies on the pollution and risk assessment of HMs in USD in oasis cities have rarely been conducted. This study systematically analyzed the enrichment status, spatial distribution, pollution levels, health risks, and sources of HMs in USD in a typical oasis city (Changji city). The results showed that the average concentrations of Pb, Ni, As, Cd, Hg, and Cu in the USD of Changji city were 46.83, 26.35, 9.92, 0.21, 0.047, and 59.33 mg/kg, respectively, and the results of the pollution index evaluation showed moderate Pb, Hg, and Cu pollution, mild Cd pollution, and no Ni or As pollution. The spatial distribution of HM concentrations in the USD was substantially heterogeneous. High values of Pb, Hg, and Cu concentrations were mainly observed in areas with relatively intensive transportation and commercial activities, and high values of Cd and Ni were observed in industrial areas. The health risk assessment showed that HMs do not pose non-carcinogenic risks to humans at their current level, but they pose a carcinogenic risk to children, with As contributing the largest carcinogenic and non-carcinogenic risks. The source identification of HMs showed that the main pollution of HMs were traffic sources for Pb and Cu, industrial sources for Ni and Cd, natural sources for As, and coal-fired sources for Hg. According to the results of the quantitative analysis with the positive matrix factorization, the contribution of pollution sources followed this order: industrial sources (31.08%) > traffic sources (26.80%) > coal-fired sources (23.31%) > natural sources (18.81%).

Genetic diversity and population dynamic of Ziziphus jujuba var. spinosa (Bunge) Hu ex H. F. Chow in Central China.

Phylogeographic research concerning Central China has been rarely conducted. Population genetic and phylogeography of Ziziphus jujuba var. spinosa (also called sour jujube) were investigated to improve our understanding of plant phylogeographic patterns in Central China. Single-copy nuclear gene markers and complete chloroplast genome data were applied to 328 individuals collected from 21 natural populations of sour jujube in China. Nucleotide variation of sour jujube was relatively high (π = 0.00720, θ w = 0.00925), which resulted from the mating system and complex population dynamics. Analysis of molecular variation analysis revealed that most of the total variation was attributed to variation within populations, and a high level of genetic differentiation among populations was detected (F st = 0.197). Relatively low long-distance dispersal capability and vitality of pollen contributed to high genetic differentiation among populations. Differences in the environmental conditions and long distance among populations further restricted gene flow. Structure clustering analysis uncovered intraspecific divergence between central and marginal populations. Migrate analysis found a high level of gene flow between these two intraspecific groups. Bayesian skyline plot detected population expansion of these two intraspecific groups. Network and phylogeny analysis of chloroplast haplotypes also found intraspecific divergence, and the divergence time was estimated to occur at about 55.86 Ma. Haplotype native to the Loess Plateau was more ancient, and multiple glacial refugia of sour jujube were found to locate at the Loess Plateau, areas adjacent to the Qinling Mountains and Tianmu Mountains. Species distribution model analysis found a typical contraction-expansion model corresponding to the Quaternary climatic oscillations. In the future, the distribution of sour jujube may shift to high-latitude areas. This study provides new insights for phylogeographic research of temperate plant species distributed in Central China and sets a solid foundation for the application of the scientific management strategy of Z. jujuba var. spinosa.

Berbamine Suppresses the Growth of Gastric Cancer Cells by Inactivating the BRD4/c-MYC Signaling Pathway.

PURPOSE: Berbamine (Ber), a bioactive constituent extracted from a traditional Chinese medicinal herb, has been shown to exhibit broad inhibitory activity on a panel of cancer cell types. However, its effects and the underlying molecular mechanisms on gastric cancer (GC) remain poorly understood. METHODS: The anti-growth activity of Ber on two GC cell lines and normal gastric epithelial cell line were evaluated using MTS and clone formation assay. Flow cytometry analysis was employed to evaluate the cell cycle distribution and apoptosis of GC cells. Western blot and quantitative PCR (qPCR) analysis were employed to investigate the anti-GC mechanism of Ber. The inhibitory activity and binding affinity of Ber against BRD4 were evaluated by homogeneous time-resolved fluorescence (HTRF) and surface plasmon resonance (SPR) assay, respectively. Molecular docking and molecular simulations were conducted to predict the interaction mode between BRD4 and Ber. RESULTS: The results demonstrated that Ber reduced the proliferation of GC cell lines SGC-7901 and BGC-823 and induced cell cycle arrest and apoptosis. Mechanistically, Ber was identified as a novel natural-derived BRD4 inhibitor through multiple experimental assay, and its anti-GC activity was probably mediated by BRD4 inhibition. Molecular modeling studies suggested that Ber might bind to BRD4 primarily through hydrophobic interactions. CONCLUSION: Our study uncovered the underlying anti-GC activity of Ber in vitro and suggested that Ber holds promise as a potential lead compound in the discovery of novel BRD4 inhibitors.

MicroRNA-126 Level Increases During Exercise Rehabilitation of Heart Failure with a Preserved Ejection Fraction.

OBJECTIVE: To evaluate the changes of plasma levels of miR-126 in heart failure with a preserved ejection fraction (HFpEF) patients undergoing an exercise rehabilitation intervention. METHODS: miR-126 levels in plasma were compared between 60HFpEF patients and 30 healthy volunteers. HFpEF patients underwent exercise rehabilitation for 12 weeks. Before and after rehabilitation, indicators of cardiac function, exercise tolerance, quality of life scores and miR-126 levels were measured and compared. Correlations between plasma levels of miR-126 and HFpEF were evaluated. RESULTS: The plasma levels of miR-126 in HFpEF patients were lower than those in healthy volunteers and increased significantly after exercise rehabilitation. HFpEF patients also showed significantly better cardiac function, exercise tolerance, and quality of life after rehabilitation. The results of Pearson correlation analysis and multiple linear regression showed that miR-126 levels were positively correlated with peak oxygen consumption (peak VO2) and metabolic equivalents (METs), and inversely associated with score on the Minnesota Living with Heart Failure Questionnaire (MLHF) as well as plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. CONCLUSION: miR-126 levels are low expressed in plasma among HFpEF patients. Effective exercise rehabilitation in HFpEF patients may positively impact the plasma level of miR-126, which is probably associated with the restoration of cardiac function, exercise tolerance and quality of life. miR-126 may be a potential biomarker for evaluating the efficacy of exercise rehabilitation for HFpEF patients.

Light-induced degradation of rhodamine B by tellurium quantum dots.

Tellurium quantum dots (Te QDs) were prepared using bulk tellurium as the precursor. Te QDs can be a highly active photocatalyst for boosting the photocatalytic degradation of rhodamine B (RhB) under visible light irradiation. The morphology and composition of Te QDs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that in the presence of H2O2, the photocatalytic efficiency of Te QDs on RhB could achieve a good degradation effect within a very short time (30 min). The effects of initial dye concentration, pH value, light intensity, catalyst dosage and H2O2 concentration on dye degradation were successively studied. The effects of inorganic ions (NO3-, Cl-, SO42-, Ca2+, Mg2+ and Fe3+) on photocatalytic degradation were also discussed. Experimental results of free radical capture showed that OH• and O2•- played important roles in photocatalytic degradation. More importantly, Te QDs efficiency still remained above 85% after four cycles of use, indicating good stability, recyclability and utility. This work may inspire further design of other semiconductor QDs for highly efficient dye degradation.

The Right-Skewed Distribution of Fine-Root Size in Three Temperate Forests in Northeastern China.

Trees can build fine-root systems with high variation in root size (e.g., fine-root diameter) and root number (e.g., branching pattern) to optimize belowground resource acquisition in forest ecosystems. Compared with leaves, which are visible above ground, information about the distribution and inequality of fine-root size and about key associations between fine-root size and number is still limited. We collected 27,573 first-order fine-roots growing out of 3,848 second-order fine-roots, covering 51 tree species in three temperate forests (Changbai Mountain, CBS; Xianrendong, XRD; and Maoershan, MES) in Northeastern China. We investigated the distribution and inequality of fine-root length, diameter and area (fine-root size), and their trade-off with fine-root branching intensity and ratio (fine-root number). Our results showed a strong right-skewed distribution in first-order fine-root size across various tree species. Unimodal frequency distributions were observed in all three of the sampled forests for first-order fine-root length and area and in CBS and XRD for first-order fine-root diameter, whereas a marked bimodal frequency distribution of first-order fine-root diameter appeared in MES. Moreover, XRD had the highest and MES had the lowest inequality values (Gini coefficients) in first-order fine-root diameter. First-order fine-root size showed a consistently linear decline with increasing root number. Our findings suggest a common right-skewed distribution with unimodality or bimodality of fine-root size and a generalized trade-off between fine-root size and number across the temperate tree species. Our results will greatly improve our thorough understanding of the belowground resource acquisition strategies of temperate trees and forests.

Ultrathin two-dimensional polydopamine nanosheets for multiple free radical scavenging and wound healing.

Novel 2D polydopamine nanosheets were successfully prepared by using a simple but effective "bottom-up" synthesis method. The ultrathin polydopamine nanosheets exhibit excellent multiple free radical scavenging activities including DPPH˙ and ABTS˙+ free radicals, especially O2˙-. Full-thickness skin defect regeneration was accelerated by treatment with the nanosheets.

Association between provincial income levels and drug prices in China over the period 2010-2017.

In the past decade, the Chinese central government has made sweeping reforms to national pharmaceutical policies. However, provincial authorities have retained control over most drug procurement procedures, potentially leading to cross-province differences in drug prices. The objectives of this study were to (i) examine drug price trends in 31 Chinese provinces and municipalities between 2010 and 2017; (ii) evaluate the association between provincial income levels and drug prices over this period; and (iii) compare the results for Chinese state-owned, Chinese private, and multinational pharmaceutical firms. Using publicly available data on procurement prices of the drugs manufactured by the top 30 pharmaceutical firms in China (in terms of revenues), we ran a generalized country-product-dummy regression to compare drug prices across provinces over the study period. We conducted subgroup analyses to test for differences between types of firms. Between 2010 and 2017, drug prices decreased by an average of 23% across the country. The prices of drugs sold by multinational firms dropped by 32% over this period, while the prices of drugs sold by Chinese private firms declined by 28%. By contrast, the drug prices of state-owned firms went up by 11%. There were statistically significant positive associations between drug prices and provincial income levels for the full sample in 2010, 2011, and 2013. There were no significant associations in other years. Several low-income provinces paid higher procurement prices than some high-income provinces for identical medicines, especially in later study years. The lack of association between income levels and prices poses equity concerns and may place a heavier cost burden on the poor. It also suggests that China's pharmaceutical policies may be failing to balance the dual aims of drug affordability and incentives for innovation.

Phillygenin, a MELK Inhibitor, Inhibits Cell Survival and Epithelial-Mesenchymal Transition in Pancreatic Cancer Cells.

INTRODUCTION: Pancreatic cancer (PC) is one of the leading causes of cancer, with the lowest 5-year survival rate of all cancer types. Given the fast metastasis of PC and its resistance to surgery, radiotherapy, chemotherapy, and combinations thereof, it is imperative to develop more effective anti-PC drugs. Phillygenin (PHI) has been reported to exert anti-cancer, anti-bacterial, and anti-inflammatory properties. However, the mechanism of PHI in the development of PC is still unclear. METHODS: The cytotoxicity of PHI in pancreatic cancer cells was evaluated by MTT assay, and clonogenic assay was used to test the anti-proliferation of PHI. The pro-apoptotic effect of PHI was detected by flow cytometry analysis. The changes of epithelial-mesenchymal transition (EMT) in pancreatic cancer cells treated with PHI were determined by Western blot. Transwell assay was used to test the migration and invasion of PC cells after treatment with PHI. Molecular docking was used to predict the potential binding site of candidate target with PHI. RESULTS: PHI could inhibit the proliferation, migration, and EMT of PC cells (PANC-1 and SW1990) and induce its apoptosis. Analysis of the Cancer Genome Atlas database indicated that elevated MELK levels correlated with poor overall survival (OS) and disease-free survival (DFS) of PC patients. In addition, molecular modeling showed that PHI may potentially target the catalytic domain of maternal embryonic leucine zipper kinase (MELK). Overexpression of MELK muted the anti-PC effects of PHI. CONCLUSION: PHI holds promise as a potent candidate drug for the treatment of PC via targeted MELK.

[Automatic Segmentation of Anatomical Areas in X-ray Images Based on Fully Convolutional Networks].

OBJECTIVE: Medical image segmentation is a key step in medical image processing. An architecture of fully convolutional networks was proposed to realize automatic segmentation of anatomical areas in X-ray images. METHODS: Enlightened by the advantages of convolutional neural networks on features extraction, fully convolutional networks consisting of 9 layers were designed to segment medical images. The networks used convolution kernels of various sizes to extract multi-dimensional image features in the images, meanwhile, eliminated pooling layers to avoid the loss of image details during downsampling procedures. RESULTS: The experiment was conducted in accordance with the specific scene of X-ray images segmentation. Compared with traditional segmentation methods, this approach achieved more accurate segmentation of anatomical areas. CONCLUSIONS: Fully convolutional networks can extract representative and multidimensional features of medical images, avoid the loss of image details during downsampling procedures, and complete automatic segmentation of anatomical areas accurately in X-ray images.

Synthesis and Near Infrared Luminescence Properties of a Series of Lanthanide Complexes with POSS Modified Ligands.

A polyhedral oligomeric silsesquioxanes (POSS) modified 8-hydroxyquinoline derivative (denoted as Q-POSS) was synthesized and used as a ligand to coordinate with lanthanide ions to obtain a series of lanthanide complexes Ln(Q-POSS)3 (Ln = Er3+, Yb3+, Nd3+). The as-prepared lanthanide complexes have been characterized by FT-IR, UV⁻Vis, and elemental analysis. All these complexes showed the characteristic near-infrared (NIR) luminescence originated from the corresponding lanthanide ions under excitation. Compared with the unmodified counterparts LnQ3 (HQ = 8-hydroxyquinoline), the Ln(Q-POSS)3 complexes showed obviously increased emission intensity, which was ascribed mainly to the steric-hindrance effects of the POSS moiety in the ligands. It is believed that the POSS group could suppress undesired excimer formation and intermolecular aggregation, thus decreasing the concentration quenching effect of the corresponding lanthanide complexes.

[Using Parallel Convolutional Neural Networks for Treatment Position Recognition in X-ray Images].

Treatment position recognition in medical images is a key technique in medical image processing. Due to the excellent performance of convolutional neural networks on features extraction and classification, an architecture of parallel convolutional neural networks is proposed to recognize treatment positions in X-ray images, which uses convolution kernels of different sizes to extract local features of different sizes in these images. The experimental analysis shows that parallel convolution neural networks, which can extract representative image features with more dimensions, are competent to classify and recognize treatment positions in medical images.

[Efficacy and safety of simulated artificial pancreas in modulating stress hyperglycemia in critically ill patients: a prospective randomized controlled study].

OBJECTIVE: To explore efficacy and safety of simulated artificial pancreas in modulating stress hyperglycemia in critically ill patients. METHODS: A prospective randomized controlled study was performed. Seventy-two critically ill patients with stress hyperglycemia, aged 18-85 years, acute physiology and chronic health evaluation II (APACHE II) score over 15, two consecutive random blood glucose 11.1 mmol/L or higher, glycated hemoglobin (HbA1C) below 0.065, unable to eat food for 3 days after inclusion, or only accepting parenteral nutrition, admitted to intensive care unit (ICU) in Shanghai Punan Hospital of Pudong New District from January 1st, 2015 to June 30th, 2017 were enrolled. The patients were divided into three groups according to the random number table method, high-intensity group and low-intensity group were injected Novolin R (high-intensity group 2/3 dosage, low-intensity group 1/3 dosage) to modulate stress hyperglycemia by simulated artificial pancreas. Simulated artificial pancreas consisted of Guardian real time glucose monitoring system (GRT system), close-circle control algorithm and micro-pump; subcutaneous injection of Humulin 70/30 was applied to modulate stress hyperglycemia in humulin group. Real-time glucose levels of interstitial fluid in abdominal wall, equivalent to blood glucose levels, 10 minutes each time, were monitored by using of GRT system for all patients in three groups. Fasting serum levels of stress hormones including epinephrine and cortisol and insulin resistance index (IRI) were recorded within 24 hours after inclusion. Mean blood glucose, blood glucose variation coefficient, blood glucose target-reaching rate, blood glucose target-reaching time, hypoglycemia rate and 6-month mortality were measured. Twenty healthy adults from health administration department of the hospital were recruited as healthy control group. RESULTS: A total of 60 eligible critically ill patients were included in this study, each group with 20 patients. There was no significant difference in gender, age, APACHE II scores among three groups. The levels of serum epinephrine, cortisol and IRI within 24 hours after inclusion in the three groups were significantly higher than those in healthy control group. The mean blood glucose levels of humulin group, low-intensity group, high-intensity group were decreased (mmol/L: 10.2±3.2, 8.4±2.6, 8.1±2.2), the blood glucose target-reaching rate were increased [40.2% (3 295/8 196), 71.1% (5 393/7 585), 80.4% (6 286/7 818)], the blood glucose target-reaching time were shortened (hours: 49.1±5.8, 24.6±4.6, 17.5±4.2), the hypoglycemia rates were increased respectively [1.3% (108/8 196), 2.8% (211/7 585), 4.0% (313/7 818)], with statistically significant differences (all P = 0.000). There was no significant difference in blood glucose variation coefficient and 6-month mortality among three groups [blood glucose variation coefficient: (29.4±3.7)%, (28.5±5.3)%, (26.1±4.6)%, 6-month mortality: 55.0%, 45.0%, 40.0%, all P > 0.05]. CONCLUSIONS: Simulated artificial pancreas could effectively and safely modulate stress hyperglycemia in critically ill patients, high-intensity modulation could bring about better efficacy in the regulation of hyperglycemia. High-frequency blood glucose monitoring by using GRT system could promptly identify hypoglycemia and help it to be corrected.

Polyphosphoric acid-induced perylene probe self-assembly and label-free fluorescence turn-on detection of alkaline phosphatase.

A label-free fluorescence turn-on strategy for alkaline phosphatase (ALP) detection was established based on its enzymatic catalyzed hydrolysis of polyphosphoric acid (PPA, an anionic polymer) that had been utilized for aggregation with our homemade positively charged perylene derivative (Probe-1) via noncovalent interactions. The disaggregation caused turn-on fluorescence signal which was recovered by the released Proble-1 molecules whose original strong fluorescence in an aqueous buffer solution had been quenched due to their previous aggregation induced by PPA. Such method presents its great advantages of free labeling, convenience and simplicity, cost effectiveness, high selectivity, and high sensitivity, with a detection limit of 0.5 mU/mL of ALP. Graphical Abstract A label-free fluorescence turn-on strategy for alkaline phosphatase based on its enzymatic catalyzed hydrolysis of polyphosphoric acid that had been utilized for aggregation with our homemade positively charged perylene derivative via noncovalent interactions.