Energy level measurement for organic semiconductors.

Along with the miniaturization and versatility of organic optoelectronic devices, it is desired to achieve a profound comprehension of the charge transport mechanism and even the basic device physics. The basis of these studies is the acquisition of relevant information about energy levels. This review provides a comprehensive analysis of five commonly-used techniques, including cyclic voltammetry, ultraviolet electron spectroscopy, inverse photoemission electron spectroscopy, low energy inverse photoemission spectroscopy and hot electron spectroscopy. According to the advantages and disadvantages, working mechanism, and application conditions, researchers will screen out a reliable and suitable characterization method, quickly and accurately. This should be beneficial for the efficient promotion of organic electronics and save valuable time for the related research studies.

Socioeconomic inequalities in cancer incidence and access to health services among children and adolescents in China: a cross-sectional study.

BACKGROUND: Despite the substantial burden caused by childhood cancer globally, childhood cancer incidence obtained in a nationwide childhood cancer registry and the accessibility of relevant health services are still unknown in China. We comprehensively assessed the most up-to-date cancer incidence in Chinese children and adolescents, nationally, regionally, and in specific population subgroups, and also examined the association between cancer incidence and socioeconomic inequality in access to health services. METHODS: In this national cross-sectional study, we used data from the National Center for Pediatric Cancer Surveillance, the nationwide Hospital Quality Monitoring System, and public databases to cover 31 provinces, autonomous regions, and municipalities in mainland China. We estimated the incidence of cancer among children (aged 0-14 years) and adolescents (aged 15-19 years) in China through stratified proportional estimation. We classified regions by socioeconomic status using the human development index (HDI). Incidence rates of 12 main groups, 47 subgroups, and 81 subtypes of cancer were reported and compared by sex, age, and socioeconomic status, according to the third edition of the International Classification of Childhood Cancer. We also quantified the geographical and population density of paediatric oncologists, pathology workforce, diagnoses and treatment institutions of paediatric cancer, and paediatric beds. We used the Gini coefficient to assess equality in access to these four health service indicators. We also calculated the proportions of cross-regional patients among new cases in our surveillance system. FINDINGS: We estimated the incidence of cancer among children (aged 0-14 years) and adolescents (aged 15-19 years) in China from Jan 1, 2018, to Dec 31, 2020. An estimated 121 145 cancer cases were diagnosed among children and adolescents in China between 2018 and 2020, with world standard age-standardised incidence rates of 122·86 (95% CI 121·70-124·02) per million for children and 137·64 (136·08-139·20) per million for adolescents. Boys had a higher incidence rate of childhood cancer (133·18 for boys vs 111·21 for girls per million) but a lower incidence of adolescent cancer (133·92 for boys vs 141·79 for girls per million) than girls. Leukaemias (42·33 per million) were the most common cancer group in children, whereas malignant epithelial tumours and melanomas (30·39 per million) surpassed leukaemias (30·08 per million) in adolescents as the cancer with the highest incidence. The overall incidence rates ranged from 101·60 (100·67-102·51) per million in very low HDI regions to 138·21 (137·14-139·29) per million in high HDI regions, indicating a significant positive association between the incidence of childhood and adolescent cancer and regional socioeconomic status (p<0·0001). The incidence in girls showed larger variation (48·45% from the lowest to the highest) than boys (36·71% from lowest to highest) in different socioeconomic regions. The population and geographical densities of most health services also showed a significant positive correlation with HDI levels. In particular, the geographical density distribution (Gini coefficients of 0·32-0·47) had higher inequalities than population density distribution (Gini coefficients of 0·05-0·19). The overall proportion of cross-regional patients of childhood and adolescent cancer was 22·16%, and the highest proportion occurred in retinoblastoma (56·54%) and in low HDI regions (35·14%). INTERPRETATION: Our study showed that the burden of cancer in children and adolescents in China is much higher than previously nationally reported from 2000 to 2015. The distribution of the accessibility of health services, as a social determinant of health, might have a notable role in the socioeconomic inequalities in cancer incidence among Chinese children and adolescents. With regards to achieving the Sustainable Development Goals, policy approaches should prioritise increasing the accessibility of health services for early diagnosis to improve outcomes and subsequently reduce disease burdens, as well as narrowing the socioeconomic inequalities of childhood and adolescent cancer. FUNDING: National Major Science and Technology Projects of China, National Natural Science Foundation of China, Chinese Academy of Engineering Consulting Research Project, Wu Jieping Medical Foundation, Beijing Municipal Administration of Hospitals Incubating Program.

Effects of attapulgite on the growth status of submerged macrophytes Vallisneria spiralis and sediment microenvironment.

The effects of raw attapulgite clay and thermally modified attapulgite clay on the growth status of submerged plant Vallisneria Spiralis (V. spiralis) and the microenvironment of sediment were first explored. The results demonstrated that the attapulgite could effectively promote the development of V. spiralis and improve plant stress resistance by enhancing the activity of antioxidant enzymes. The 10% addition of attapulgite clay increased the biomass of V. spiralis by 27%∼174%, and the promoted rate of raw attapulgite clay was 2∼5 times of modified attapulgite clay. The attapulgite increased redox potential in sediment (P < 0.05) and provided proper niches for organism propagation, further promoting the degradation of organic matter and nutrient metabolism in sediment. The value of Shannon, Chao, and Ace was 9.98, 4865.15, 5029.08 in the 10% modified attapulgite group, and 10.12, 4856.85, 4947.78 in the 20% raw attapulgite group, respectively, indicating that the attapulgite could increase the microbial diversity and abundance in sediment. Additionally, the nutrient elements, such as Ca, Na, S, Mg, K, Zn, and Mo, that dissolved from attapulgite may also promote the V. spiralis growth. This study provided an environment-friendly approach to facilitating submerged macrophyte restoration in the eutrophic lake ecosystem.

Study on adsorption and recovery utilization of phosphorus using alkali melting-hydrothermal treated oil-based drilling cutting ash.

Oil-based drill cutting ash (OBDCA) was treated by alkali melting-hydrothermal method and used as novel adsorbent (AM-HT-OBDCA) for the recovery of phosphorus (P) in water body. The experiment parameter for preparation of AM-HT-OBDCA was optimized, including alkali melting ratio (MOBDCA: MNaOH), alkali melting temperature and hydrothermal temperature. The adsorption process of phosphorus on AM-HT-OBDCA was fit well with the pseudo-second-order model and the Langmuir model. The calculated theoretic adsorption capacity of phosphorus on AM-HT-OBDCA was 62.9 mg/g. The adsorption behavior was spontaneous and endothermic. The effect of pH value and interfering ions on the adsorption of phosphorus in AM-HT-OBDCA was investigated. The main existing form of adsorbed phosphorus on AM-HT-OBDCA was sodium hydroxide extraction form phosphorus (NaOH-P), including iron form phosphorus (Fe-P) and aluminum form phosphorus (Al-P). Precipitation and ligand exchange were the main mechanisms of phosphorus adsorption on AM-HT-OBDCA. The AM-HT-OBDCA used for phosphorus adsorption (AM-HT-OBDCA-P) could be further utilized as fertilizer to promote plant growth. The results of this study provide fundamental data and evaluation support for resource utilization of OBDCA. These results will also provide a reference for the adsorption and recovery utilization of phosphorus using solid waste-based adsorbent.

A novel energy level detector for molecular semiconductors.

The multifunction of molecule-based devices is always achieved by improving their charge transport characteristics. These characteristics depend strongly on the energy levels of molecular semiconductors, which fundamentally govern the working principle and device performance. Therefore, an accurate measurement of these energy levels is crucial for evaluating the availability of the prepared materials and thus optimizing the device performance. Here, an easy-to-operate three-terminal hot electron transistor has been developed, which comprises a molecular optoelectronic device that records the charge transport. It achieves exceptional properties including the lowest unoccupied molecular orbit level, highest occupied molecular orbit level, higher energy states, and higher electronic bandgap. When compared with existing techniques such as cyclic voltammetry, inverse photoemission spectroscopy, and ultraviolet photoemission spectroscopy, the hot electron transistor provides in-situ characterization and categorizes the measured energy information as intrinsic properties of the molecular semiconductor. Furthermore, we provide an in-depth understanding of the fundamental device-physics, which provides promising guidance for performance optimization.

Effects of vermiculite on the growth process of submerged macrophyte Vallisneria spiralis and sediment microecological environment.

Ecological restoration is one of the hot technologies for the reconstruction of eutrophic lake ecosystems in which the restoration and propagation of submerged plants is the key and difficult step. In this paper, the effect of vermiculite on the growth process of Vallisneria spiralis and sediment microenvironment were investigated, aiming to provide a theoretical basis for the application of vermiculite in aquatic ecological restoration. Results of growth indexes demonstrated that 5% and 10% vermiculite treatment groups statistically promote the growth of Vallisneria spiralis compared to the control. Meanwhile, the results of ecophysiological indexes showed that photosynthetic pigment, soluble sugar content, superoxide dismutase (SOD), and catalase (CAT) activity of 5% and 10% group were increased compared with the control while the malondialdehyde (MDA) content exhibited the opposite result (p < 0.05), which illustrated that vermiculite can improve the resistance of plants and delay the aging process of Vallisneria spiralis. In addition, result of PCA (Principal Component Analysis) demonstrated 5% and 10% group has improved the sediment physical conditions and create more ecological niche for microorganisms directly, and then promoted the growth of plants. The dissolution results showed that vermiculite can dissolve the constant and trace elements needed for plant growth. Furthermore, the addition of vermiculite increased the diversity of microorganisms in the sediments, and promoted the increase of plant growth-promoting bacteria and phosphorus-degrading bacteria. This study could provide a technique reference for the further application of vermiculite in the field of ecological restoration.

Favorable Electrochemical Performance of LiMn2O4/LiFePO4 Composite Electrodes Attributed to Composite Solid Electrolytes for All-Solid-State Lithium Batteries.

Li1.5Al0.5Ge1.5(PO4)3 (LAGP)-PEO composite electrolytes are unstable in LiMn2O4. In addition, the discharge platform potential (2.8 and 4.0 V) difference of LiMn2O4 is relatively large, whereas the discharge platform potential (3.5 V) of LiFePO4 is between 2.8 and 4.0 V. Thus, LiMn2O4 and LiFePO4 can be compounded together to reduce the material platform voltage difference and obtain the advantages of both materials at the same time. Here, LiMn2O4/LiFePO4 composite cathodes were applied in solid-state batteries. LAGP-PEO(LiTFSI) was used as the electrolyte. The Li/composite cathode battery using composite electrolytes has a reversible capacity of 192.8 mAh g-1 at 50 °C and 0.1 C. It possesses favorable rate performance and exhibits very good cycling stability. In addition, the composite electrolytes can prevent the further occurrence of the Jahn-Teller effect. Meanwhile, the charge-transfer resistance slightly decreases in 10 cycles. The excellent capacity retention of the battery is connected with the excellent electrochemical stability and the well-interfaced contacts of the composite electrolytes with electrodes.

CBDPS 1.0: A Python GUI Application for Machine Learning Models to Predict Bitter-Tasting Children's Oral Medicines.

Bitter tastes are innately aversive and are thought to help protect animals from consuming poisons. Children are extremely sensitive to drug tastes, and their compliance is especially poor with bitter medicine. Therefore, judging whether a drug is bitter and adopting flavor correction and taste-masking strategies are key to solving the problem of drug compliance in children. Although various machine learning models for bitterness and sweetness prediction have been reported in the literature, no learning model or bitterness database for children's medication has yet been reported. In this study, we trained four different machine learning models to predict bitterness. The goal of this study was to develop and validate a machine learning model called the "Children's Bitter Drug Prediction System" (CBDPS) based on Tkinter, which predicts the bitterness of a medicine based on its chemical structure. Users can enter the Simplified Molecular-Input Line-Entry System (SMILES) formula for a single compound or multiple compounds, and CBDPS will predict the bitterness of children's medicines made from those XGBoost-Molecular ACCess System (XgBoost-MACCS) model yielded an accuracy of 88% under cross-validation.

Effects of bentonite on the growth process of submerged macrophytes and sediment microenvironment.

The effects of clay mineral bentonite on the growth process of submerged macrophyte V. spiralis and sediment microenvironment were investigated in the study for the first time, aiming to determine whether it is suitable for application in the field of ecological restoration. The growth index, and physiological and biochemical index of V. spiralis in the experiments were measured once a month, and the changes of rhizosphere microorganisms and physicochemical properties of sediments were also studied at the same time. The results demonstrated that bentonite can effectively promote the growth of V. spiralis. The treatment groups of RB1/1 and MB1/5 (the mass ratios of bentonite to sediment were 1/1 and 1/5, respectively.) showed the best V. spiralis growth promotion rates which were 18.78%, and 11.79%, respectively. The highest microbial diversity and abundance existed in group of RB10 (the mass ratio of sediment to bentonite was 10/1), in which the OTUs, Shannon, Chao and Ace were 1521.0, 5.20, 1712.26, and 1686.31, respectively. Bentonite was conducive to the propagation of rhizosphere microorganisms, and further changed the physical and chemical properties of the sediment microenvironment. The nutrient elements dissolved from bentonite may be one of the main reasons that promoted the growth of V. spiralis. The purpose of this result is to prove that bentonite can be further applied as sediment improver and growing media in ecological restoration projects in eutrophic shallow lakes.

Histone deacetylase 3-selective inhibitor RGFP966 ameliorates impaired glucose tolerance through ß-cell protection.

The potential therapeutic effect of histone deacetylase 3 (HDAC3) pharmacologic inhibition on diabetes has been focused recently. RGFP966, as a highly-selective HDAC3 inhibitor, its possible roles and underlying mechanism in the treatment of diabetes needs to be clarified. In this study, low-dose streptozotocin (STZ)-induced pre-diabetic mice were used to test the regulatory ability of RGFP966 in blood glucose and insulin. We isolated the islets both from normal C57BL/6 J mice and KKAy mice with spontaneous type 2 diabetes to determine the potency of RGFP966 on glucose-stimulated insulin secretion. NIT-1 pancreatic ß-cells induced by sodium palmitate (PA) were applied to identify the protective effects of RGFP966 against ß-cell apoptosis. The results showed that administration of RGFP966 in the pre-diabetic mice not only significantly reduced hyperglycemia, promoted phase I insulin secretion, improved morphology of islets, but also increased glucose infusion rate (GIR) during hyperglycemic clamp test. When treated in vitro, RGFP966 enhanced insulin secretion and synthesis in islets of normal C57BL/6J mice and diabetic KKAy mice. In addition, it partially attenuated PA-induced apoptosis in NIT-1 cells. Therefore, our research suggests that RGFP966, probably through selective inhibition of HDAC3, might serve as a novel potential preventive and therapeutic candidate for diabetes.

Berberine combined with stachyose induces better glycometabolism than berberine alone through modulating gut microbiota and fecal metabolomics in diabetic mice.

Berberine (BBR), a small alkaloid, is used as a hypoglycemic agent in China. Stachyose (Sta), a Rehmannia glutinosa oligosaccharide, acts as a prebiotic. This study aimed to evaluate whether BBR combined with Sta produced better glycometabolism than BBR alone, and explored the effects on gut microbiota and metabolomics. Type-2 diabetic db/db mice were administered BBR (100 mg/kg), Sta (200 mg/kg), or both by gavage once daily. Glucose metabolism, the balance of α- and ß-cells, and mucin-2 expression were ameliorated by combined treatment of BBR and Sta, with stronger effects than upon treatment with BBR alone. The microbial diversity and richness were altered after combined treatment and after treatment with BBR alone. The abundance of Akkermansia muciniphila was increased by combined treatment compared to treatment with BBR alone, while the levels of the metabolite all-trans-heptaprenyl diphosphate were decreased and the levels of fumaric acid were increased, which both showed a strong correlation with A. muciniphila. In summary, BBR combined with Sta produced better glycometabolism than BBR alone through modulating gut microbiota and fecal metabolomics, and may aid in the development of a novel pharmaceutical strategy for treating Type 2 diabetes mellitus.

A novel specific peroxisome proliferator-activated receptor γ (PPARγ) modulator YR4-42 ameliorates hyperglycaemia and dyslipidaemia and hepatic steatosis in diet-induced obese mice.

AIMS: To evaluate a novel tetrahydroisoquinoline derivative YR4-42 as a selective peroxisome proliferator-activated receptor γ (PPARγ) modulator (SPPARM) and explore its anti-diabetic effects in vitro and in vivo. MATERIALS AND METHODS: Using two standard full PPARγ agonists rosiglitazone and pioglitazone as controls, the PPARγ binding affinity and transactivation action of YR4-42 were evaluated using biochemical and cell-based reporter gene assays. The capacity of YR4-42 to recruit coactivators of PPARγ was also assessed. The effects of YR4-42 on adipogenesis and glucose consumption and PPARγ Ser273 phosphorylation were investigated in 3T3-L1 adipocytes. The effects of YR4-42 and pioglitazone, serving as positive control, on glucose and lipids metabolism were investigated in high-fat diet-induced obese (DIO) C57BL/6J mice. The expression of PPARγ target genes involved in glucose and lipid metabolism was also assessed in vitro and in vivo. RESULTS: In vitro biochemical and cell-based functional assays showed that YR4-42 has much weaker binding affinity, transactivation, and recruitment to PPARγ of the coactivators thyroid hormone receptor-associated protein complex 220 kDa component (TRAP220) and PPARγ coactivator 1-α (PGC1α) compared to full agonists. In 3 T3-L1 adipocytes, YR4-42 significantly improved glucose consumption without a lipogenesis effect, while blocking tumour necrosis factor α-mediated phosphorylation of PPARγ at Ser273, thereby upregulating the expression of the PPARγ Ser273 phosphorylation-dependent genes. Furthermore, in DIO mice, oral administration of YR4-42 ameliorated the hyperglycaemia, with a similar insulin sensitization effect to that of pioglitazone. Importantly, YR4-42 also improved hyperlipidaemia-associated hepatic steatosis without weight gain, which avoids a major side effect of pioglitazone. Thus, YR4-42 appeared to selectively modulate PPARγ responses. This finding was supported by the gene expression analysis, which showed that YR4-42 selectively targets PPARγ-regulated genes mapped to glucose and lipid metabolism in DIO mice. CONCLUSIONS: We conclude that YR4-42 is a novel anti-diabetic drug candidate with significant advantages compared to standard PPARγ agonists. YR4-42 should be further investigated in preclinical and clinical studies.

Silicate-based mineral materials promote submerged plant growth: Insights from plant physiology and microbiomes.

Restoring submerged plants naturally has been a significant challenge in water ecology restoration programs. Some silicate-based mineral materials have shown promise in improving the substrate properties for plant growth. While it is well-established that silicate mineral materials enhance submerged plant growth by improving salt release and reducing salt stress, the influence of rhizosphere microorganisms on phytohormone synthesis and key enzyme activities has been underestimated. This study focused on two typical silicate mineral materials, bentonite and maifanite, to investigate their effects on Myriophyllum oguraense from both plant physiology and microbiome perspectives. The results demonstrated that both bentonite and maifanite regulated the synthesis of phytohormones such as gibberellin (GA) and methyl salicylate (MESA), leading to inhibition of cellular senescence and promotion of cell division. Moreover, these silicate mineral materials enhanced the activity of antioxidant enzymes, thereby reducing intracellular reactive oxygen species levels. They also optimized the structure of rhizosphere microbial communities, increasing the proportion of functional microorganisms like Nitrospirota and Sva0485, which indirectly influenced plant metabolism. Analysis of sediment physicochemical properties revealed increased rare earth elements, macronutrients, and oxygen content in pore water in the presence of silicate materials, creating favorable conditions for root growth. Overall, these findings shed light on the multifaceted mechanisms by which natural silicate mineral materials promote the growth of aquatic plants, offering a promising solution for restoring aquatic vegetation in eutrophic lake sediments.

Unraveling the nuclear isotope tapestry: Applications, challenges, and future horizons in a dynamic landscape.

Nuclear isotopes, distinct atoms characterized by varying neutron counts, have profoundly influenced a myriad of sectors, spanning from medical diagnostics and therapeutic interventions to energy production and defense strategies. Their multifaceted applications have been celebrated for catalyzing revolutionary breakthroughs, yet these advancements simultaneously introduce intricate challenges that warrant thorough investigation. These challenges encompass safety protocols, potential environmental detriments, and the complex geopolitical landscape surrounding nuclear proliferation and disarmament. This comprehensive review embarks on a deep exploration of nuclear isotopes, elucidating their nuanced classifications, wide-ranging applications, intricate governing policies, and the multifaceted impacts of their unintended emissions or leaks. Furthermore, the study meticulously examines the cutting-edge remediation techniques currently employed to counteract nuclear contamination while projecting future innovations in this domain. By weaving together historical context, current applications, and forward-looking perspectives, this review offers a panoramic view of the nuclear isotope landscape. In conclusion, the significance of nuclear isotopes cannot be understated. As we stand at the crossroads of technological advancement and ethical responsibility, this review underscores the paramount importance of harnessing nuclear isotopes' potential in a manner that prioritizes safety, sustainability, and the greater good of humanity.

Submerged macrophyte restoration enhanced microbial carbon utilization in shallow lakes.

Submerged macrophytes are integral to the functioning of shallow lakes through their interaction with microorganisms. However, we have a limited understanding of how microbial communities in shallow lakes respond when macrophytes are restored after being historically extirpated. Here, we explored the interactions between prokaryotic communities and carbon utilization in two lakes where submerged macrophytes were restored. We found restoration reduced total carbon in sediment by 8.9 %-27.9 % and total organic carbon by 16.7 %-36.9 % relative to control treatment, but had no effects on carbon content in the overlying water. Sediment microbial communities were more sensitive to restoration than planktonic microbes and showed enhanced utilization of simple carbon substrates, such as Tween 40, after restoration. The increase in carbon utilization was attributed to declines in the relative abundance of some genera, such as Saccharicenans and Desertimonas, which were found weakly associated with the utilization of different carbon substrates. These genera likely competed with microbes with high carbon utilization in restored areas, such as Lubomirskia. Our findings highlight how restoring submerged macrophytes can enhance microbial carbon utilization and provide guidance to improve the carbon sequestration capacity of restored shallow lakes.

Combined remediation mechanism of bentonite and submerged plants on lake sediments by DGT technique.

The diffusive gradients in thin films (DGT) technique was applied to determine the mechanism by which bentonite improves the eutrophic lake sediment microenvironment and enhances submerged plant growth. The migration dynamics of N, P, S, and other nutrient elements were established for each sediment layer and the remediation effects of bentonite and submerged plants on sediments were evaluated. Submerged plant growth in the bentonite group was superior to that of the Control. At harvest time, the growth of Vallisneria spiralis and Hydrilla verticillata was optimal on a substrate consisting of five parts eutrophic lake sediment to one part modified bentonite (MB5/1). Bentonite addition to the sediment was conducive to rhizosphere microorganism proliferation. Microbial abundance was highest under the MB5/1 treatment whilst microbial diversity was highest under the RB1/1 (equal parts raw bentonite and eutrophic lake sediment) treatment. Bentonite addition to the sediment may facilitate the transformation of nutrients to bioavailable states. The TP content of the bentonite treatment was 22.47%-46.70% lower than that of the Control. Nevertheless, the bentonite treatment had higher bioavailable phosphorus (BIP) content than the control. The results of this study provide theoretical and empirical references for the use of a combination of modified bentonite and submerged plants to remediate eutrophic lake sediment microenvironments.

Long-term study of ecological restoration in a typical shallow urban lake.

We investigated the long-term effects (6 years) of sediment improvement and submerged plant restoration of a subtropical shallow urban lake, Hangzhou West Lake China. To reveal the lake ecosystems variations, we analyzed the sediment properties, submerged macrophyte characteristics, sediment microorganisms, and benthic macroinvertebrate communities from 2015 to 2020. The ecological restoration project decreased sediment TP and OM, increased submerged macrophyte biomass and sediment microbial diversity, and improved the benthic macroinvertebrate communities in the restored area. The sediment TP decreased from 2.94 mg/g in 2015 to 1.33 mg/g in 2020. The sediment OM of the restored area decreased from 27.44 % in 2015 to 8.08 % in 2020. Principal component analysis (PCA) confirmed that the restoration improved the sediment conditions, making it suitable for the growth of submerged macrophytes, and then sped up the restoration and reconstruction of the lake ecosystem. These results have significant implications on the ecological management of shallow lakes.

A novel polymer electrolyte with high elasticity and high performance for lithium metal batteries.

A polymer electrolyte with high elasticity and high performance is prepared by IN SITU polymerization. The polymer electrolyte is amorphous and has a high ionic conductivity of 7.9 × 10-4 S cm-1 and good elasticity. The discharge capacity of Li/LiFePO4 in the 100th cycle is 133.90 mA h g-1 (0.5C, 25 °C).

Changes of microbial community structure during the initial stage of biological clogging in horizontal subsurface flow constructed wetlands.

The clogging is a universal problem in constructed wetlands, where microorganisms play an essential role. However, the implication of micro-organism variation due to the clogging is not clear. Four horizontal subsurface flow constructed wetlands (HFCWs) were designed and operated to simulate the process of clogging. The wetland treatment performance and microbial community variation were investigated by regularly monitoring. Results showed the substrate filtration rate and the total phosphorous (TP) removal efficiency consistently decreased and the chemical oxygen demand (COD) and total nitrogen (TN) removal efficiency were at the range of 50%-85% and 10-20%, respectively. The sequencing results indicated that the clogging could affect the richness of bacterial community. The bacterial variation could be attributed to the dissolved oxygen decreasing and organic matter accumulation in the initial clogging period. These findings are expected to provide some theoretical reference for developing the biological methods to indicate the initial clogging in constructed wetlands.