Assessment of pathogenicity and functional characterization of APPL1 gene mutations in diabetic patients.

BACKGROUND: Adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1) plays a crucial role in regulating insulin signaling and glucose metabolism. Mutations in the APPL1 gene have been associated with the development of maturity-onset diabetes of the young type 14 (MODY14). Currently, only two mutations [c.1655T>A (p.Leu552*) and c.281G>A p.(Asp94Asn)] have been identified in association with this disease. Given the limited understanding of MODY14, it is imperative to identify additional cases and carry out comprehensive research on MODY14 and APPL1 mutations. AIM: To assess the pathogenicity of APPL1 gene mutations in diabetic patients and to characterize the functional role of the APPL1 domain. METHODS: Patients exhibiting clinical signs and a medical history suggestive of MODY were screened for the study. Whole exome sequencing was performed on the patients as well as their family members. The pathogenicity of the identified APPL1 variants was predicted on the basis of bioinformatics analysis. In addition, the pathogenicity of the novel APPL1 variant was preliminarily evaluated through in vitro functional experiments. Finally, the impact of these variants on APPL1 protein expression and the insulin pathway were assessed, and the potential mechanism underlying the interaction between the APPL1 protein and the insulin receptor was further explored. RESULTS: A total of five novel mutations were identified, including four missense mutations (Asp632Tyr, Arg633His, Arg532Gln, and Ile642Met) and one intronic mutation (1153-16A>T). Pathogenicity prediction analysis revealed that the Arg532Gln was pathogenic across all predictions. The Asp632Tyr and Arg633His variants also had pathogenicity based on MutationTaster. In addition, multiple alignment of amino acid sequences showed that the Arg532Gln, Asp632Tyr, and Arg633His variants were conserved across different species. Moreover, in in vitro functional experiments, both the c.1894G>T (at Asp632Tyr) and c.1595G>A (at Arg532Gln) mutations were found to downregulate the expression of APPL1 on both protein and mRNA levels, indicating their pathogenic nature. Therefore, based on the patient's clinical and family history, combined with the results from bioinformatics analysis and functional experiment, the c.1894G>T (at Asp632Tyr) and c.1595G>A (at Arg532Gln) mutations were classified as pathogenic mutations. Importantly, all these mutations were located within the phosphotyrosine-binding domain of APPL1, which plays a critical role in the insulin sensitization effect. CONCLUSION: This study provided new insights into the pathogenicity of APPL1 gene mutations in diabetes and revealed a potential target for the diagnosis and treatment of the disease.

Blind Video Quality Assessment for Ultra-High-Definition Video Based on Super-Resolution and Deep Reinforcement Learning.

Ultra-high-definition (UHD) video has brought new challenges to objective video quality assessment (VQA) due to its high resolution and high frame rate. Most existing VQA methods are designed for non-UHD videos-when they are employed to deal with UHD videos, the processing speed will be slow and the global spatial features cannot be fully extracted. In addition, these VQA methods usually segment the video into multiple segments, predict the quality score of each segment, and then average the quality score of each segment to obtain the quality score of the whole video. This breaks the temporal correlation of the video sequences and is inconsistent with the characteristics of human visual perception. In this paper, we present a no-reference VQA method, aiming to effectively and efficiently predict quality scores for UHD videos. First, we construct a spatial distortion feature network based on a super-resolution model (SR-SDFNet), which can quickly extract the global spatial distortion features of UHD videos. Then, to aggregate the spatial distortion features of each UHD frame, we propose a time fusion network based on a reinforcement learning model (RL-TFNet), in which the actor network continuously combines multiple frame features extracted by SR-SDFNet and outputs an action to adjust the current quality score to approximate the subjective score, and the critic network outputs action values to optimize the quality perception of the actor network. Finally, we conduct large-scale experiments on UHD VQA databases and the results reveal that, compared to other state-of-the-art VQA methods, our method achieves competitive quality prediction performance with a shorter runtime and fewer model parameters.

Bioequivalence evaluation and food effect assessment of Lisinopril/amlodipine tablets in healthy Chinese subjects under fasting and fed conditions.

PURPOSE: The combination of lisinopril and amlodipine has a marked additional effect on blood pressure and fewer side effects than individual monotherapy. This study was conducted to compare the pharmacokinetic parameters and evaluate the bioequivalence between two Lisinopril/amlodipine tablets in healthy Chinese subjects. METHODS: A single center, randomized, open-label, single-dose, two-period crossover bioequivalence study was designed in healthy Chinese subjects under both fasting and fed conditions. Blood samples were collected before drug administration and at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 24, 36, 48, 72, 96, 144, 168 h after administration. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to determine the plasma concentration of lisinopril and amlodipine. Maximum concentration (Cmax) and area under the concentration-time curve (AUC) were used to evaluate bioequivalence. Adverse events were recorded. RESULTS: Ninety-two healthy subjects were enrolled, and 75 completed the study. The 90% confidence intervals (CIs) of the ratio of geometric means (GMRs) of Cmax, AUC0-t, and AUC0-∞ of lisinopril and amlodipine under both fasting and fed conditions fell within the conventional bioequivalence criteria of 0.80-1.25. A high-fat meal appeared to decrease the Cmax and AUC of lisinopril. No severe adverse events were observed. CONCLUSION: The trial demonstrated that the test and the reference lisinopril/amlodipine tablets were bioequivalent and well tolerated in Chinese people under fasting and fed conditions. TRIAL REGISTRATION: Clinical Trails.gov identifier, NCT04885660 (retrospectively registered in 13/05/ 2021).

Bioequivalence and Food Effect Assessment of 2 Rivaroxaban Formulations in Healthy Chinese Volunteers: An Open, Randomized, Single-Dose, and 4-Period Crossover Study.

Rivaroxaban is a direct factor Xa inhibitor used for the management of thromboembolic disorders. The aim of this study was to evaluate the safety, pharmacokinetic profile, and bioequivalence of a generic and a branded rivaroxaban formulation (Xarelto) under fasted and fed conditions in healthy Chinese volunteers. An open-label, randomized, single-dose, 4-period complete, and replicate crossover study in healthy Chinese volunteers was performed. A single oral dose of 20 mg of 2 rivaroxaban formulations was administered to 72 healthy volunteers, with 36 in the fasted group and 36 consuming a high-fat diet. The evaluated pharmacokinetic parameters, including maximum rivaroxaban concentration, the area under the concentration-time curve (AUC) from time 0 to the last measurable concentration, and AUC from time 0 to infinity, were assessed for BE. The plasma concentrations of rivaroxaban were measured by a validated liquid chromatography-tandem mass spectrometry method. The geometric mean ratios with 90% confidence intervals of the maximum rivaroxaban concentration, AUC from time 0 to the last measurable concentration, and AUC from time 0 to infinity were all within the range of 80% to 125% under fasted and fed conditions. The within-subject variability of the test and reference products was compared, and the upper limit of the 90% confidence intervals for the test-to-reference ratio of the within-subject variability was <2.5, which indicated that the rivaroxaban test and the rivaroxaban reference formulation were bioequivalent. No serious adverse events were reported during either fasted or fed conditions of the study.

Impacts of age, diabetes, gender, and access type on costs associated with vascular access among Chinese patients on hemodialysis.

OBJECTIVES: Examine the impacts of age, diabetes, gender, and access type on vascular access (VA) associated costs among Chinese hemodialysis (HD) patients. METHODS: We retrospectively included patients whose first permanent VA was created at the West China Hospital. Clinical characteristics, maturation, intervention, utilization, and exchange of every VA, as well as VA-related infection were collected. The study period for each patient was from HD initiation to the last follow-up. VA-related costs, including those for placement and intervention procedures, were calculated according to the standards set in 2019 for Chinese tertiary hospitals. Mann-Whitney U and Chi-square tests were conducted for comparisons between groups. RESULTS: A total of 358 Chinese HD patients experienced functionally 143 arteriovenous fistula (AVF), 22 arteriovenous graft (AVG), and 439 tunneled cuffed central venous catheter (tcCVC) during a median study period of 26 (IQR 13-44) months, of which 42.5% used more than one permanent VA. The median annual VA-related cost in the groups of age >75 years and ⩽75 years, diabetes and non-diabetes, male and female, was $525 and $397 (p = 0.016), $459 and $462 (p = 0.64), $476 and $445 (p = 0.94), respectively. The median monthly costs for AVF ($18), AVG ($289), and tcCVC ($37) were significantly different. CONCLUSION: HD patients aged >75 years had significantly higher annual VA-related costs. However, the annual VA-related costs did not differ across the diabetes groups or the gender groups. AVF was the most cost-effective permanent VA type in China, partly due to the inexpensive materials used compared to AVG or tcCVC.

A flexible and cost-effective manual droplet operation platform for miniaturized cell assays and single cell analysis.

Herein, we developed a flexible and cost-effective manual droplet operation system (MDOS) for performing miniaturized cell assays as well as single cell analysis. The MDOS consists of a manual x-y-z translation stage for liquid transferring and switching, a high-precision syringe pump for liquid driving and metering, a tapered capillary probe for droplet manipulation, a droplet array chip for droplet loading and reaction, sample/reagent reservoirs for storage, and a microscope for droplet observation, with a total expense of only $4,000. By using the flexible combination of three elementary operations of the x-y-z stage's moving and the pump's aspirating and depositing, the MDOS can manually achieve multiple droplet handling operations in the nanoliter to picoliter range, including droplet generation, assembling, fusion, diluting, and splitting. On this basis, multiple cell-related operations could be performed, such as nanoliter-scale in-droplet cell culture, cell coculture, drug stimulation, cell washing, and cell staining, as well as formation of picoliter single-cell droplets. The feasibility and flexibility of the MDOS was demonstrated in multi-mode miniaturized cell assays, including cell-based drug test, first-pass effect assay, and single-cell enzyme assay. The MDOS with the features of low cost, easy to build and flexible to use, could provide a promising alternative for performing miniaturized assays in routine laboratories, in addition to conventional microfluidic chip-based systems and automated robot systems.

Assessment of Temperature-Hand, Foot, and Mouth Disease Association and Its Variability across Urban and Rural Populations in Wuxi, China: A Distributed Lag Nonlinear Analysis.

Hand, foot, and mouth disease (HFMD) has brought millions of attacks and a substantial burden in the Asia-Pacific region. Previous studies assessed disease risks around the world, which demonstrated great heterogeneity, and few determined the modification effect of social factors on temperature-disease relationship. We conducted a time-series study to evaluate the temperature-associated HFMD morbidity risk using daily data (from 2011 to 2017) and to identify potential modifiers relating to urban-rural status and aggregation mode of children. By applying a distributed lag nonlinear model (DLNM) and controlling for time-varying factors and other meteorological factors, we found that the relationship between daily mean temperature and the cumulative risk of HFMD was an approximately M-shaped curve. The effects of higher temperature appeared to be greater and more persistent than those of lower temperature. With the reference of -6°C, the cumulative relative risk (RR) values of high temperature (95 percentile) and low temperature (5 percentile) were 3.74 (95% CI: 2.50-5.61) and 1.72 (95% CI: 1.24-2.37) at lag 4-7, respectively. Temperature-associated HFMD morbidity risks were more pronounced among rural children and those attending kindergartens or schools at specific lags and temperatures. Relative risk values for temperature-disease association was highest among the 3- to 6-year group, whereas no gender difference was observed. Studying effect estimates and their modifications using the DLNM on a daily scale helps to identify susceptible groups and guide policy-making and resource allocation according to specific local conditions.

Assessment of Renal Function and Risk Factors for Chronic Kidney Disease in Patients With Peripheral Arterial Disease.

Chronic kidney disease (CKD) and peripheral arterial disease (PAD) share common risk factors. We assessed renal function and the prevalence of CKD in patients with PAD and investigated the characteristics of the risk factors for CKD in this population. Renal function of 421 patients with PAD was evaluated. Among the participants, 194 (46.1%) patients had decreased estimated glomerular filtration rate (eGFR). The prevalence of CKD was much higher among patients with PAD. Hypertension (odds ratios [ORs] 2.156, 95% confidence interval [CI] 1.413-3.289, P < .001), serum uric acid (OR 3.794, 95% CI 2.220-6.450, P < .001), and dyslipidemia (OR 1.755, 95% CI 1.123-2.745, P = .014) were significantly associated with CKD and the independent risk factors for CKD in patients with PAD. CKD is common and has a high prevalence in a population with PAD. Patients with PAD may be considered as a high-risk population for CKD. Recognition and modification of risk factors for CKD might beneficially decrease CKD incidence and improve prognosis in patients with PAD.

Assessment of different route choice on commuters' exposure to air pollution in Taipei, Taiwan.

The purposes of this study are to develop a healthy commute map indicating cleanest route in Taipei metropolitan area for any given journey and to evaluate the pollutant doses exposed in different commuting modes. In Taiwan, there are more than 13.6 million motorcycles and 7.7 million vehicles among the 23 million people. Exposure to traffic-related air pollutants can thus cause adverse health effects. Moreover, increasing the level of physical activity during commuting and longer distances will result in inhalation of more polluted air. In this study, we utilized air pollution monitoring data (CO, SO2, NO2, PM10, and PM2.5) from Taiwan EPA's air quality monitoring stations in Taipei metropolitan area to estimate each pollutant exposure while commuting by different modes (motorcycling, bicycling, and walking). Spatial interpolation methods such as inverse distance weighting (IDW) were used to estimate each pollutant's distribution in Taipei metropolitan area. Three routes were selected to represent the variety of different daily commuting pathways. The cleanest route choice was based upon Dijkstra's algorithm to find the lowest cumulative pollutant exposure. The IDW interpolated values of CO, SO2, NO2, PM10, and PM2.5 ranged from 0.42-2.2 (ppm), 2.6-4.8 (ppb), 17.8-42.9 (ppb), 32.4-65.6 (µg/m3), and 14.2-38.9 (µg/m3), respectively. To compare with the IDW results, concentration of particulate matter (PM10, PM2.5, and PM1) along the motorcycle route was measured in real time. In conclusion, the results showed that the shortest commuting route for motorcyclists resulted in a much higher cumulative dose (PM2.5 3340.8 µg/m3) than the cleanest route (PM2.5 912.5 µg/m3). The mobile personal monitoring indicated that the motorcyclists inhaled significant high pollutants during commuting as a result of high-concentration exposure and short-duration peaks. The study could effectively present less polluted commuting routes for citizen health benefits.

Review on Natural Enemies and Diseases in the Artificial Cultivation of Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes).

Ophiocordyceps sinensis (syn. Cordyceps sinensis), well known as DongChongXiaCao (DCXC), is one of the most valuable traditional Chinese medicinal species. In this article, we provide a systematic review of natural enemies and diseases encountered in artificial cultivation of DCXC. Unfortunately, DCXC has been endangered over the past decades due to overharvesting and a worsening ecological environment. Therefore, the artificial cultivation of DCXC has been extensively investigated in recent years. Complete indoor artificial cultivation and semi-field cultivation are the two most common strategies used to cultivate DCXC. However, cultured DCXCs are often attacked by various natural enemies and diseases, which have resulted in substantial loss of the valuable medicinal resource. In this study, we have summarized the species of natural enemies and types of diseases confronted by DCXC. Twenty reported natural enemy species are categorized into four classes, one of which is reported for the first time in this study. Moreover, six microbial pathogens are also discussed. The recapitulation of the natural enemies and diseases in DCXC artificial cultivation not only promote the development of integrated pest management of DCXC cultivation but also provide important information to help preserve and develop this valuable resource.

[Application of linear and nonlinear characteristics of heart rate variability in assessment of autonomic nervous system activity].

Calculation of linear parameters, such as time-domain and frequency-domain analysis of heart rate variability (HRV), is a conventional method for assessment of autonomic nervous system activity. Nonlinear phenomena are certainly involved in the genesis of HRV. In a seemingly random signal the Poincaré plot can easily demonstrate whether there is an underlying determinism in the signal. Linear and nonlinear analysis methods were applied in the computer words inputting experiments in this study for physiological measurement. This study therefore demonstrated that Poincaré plot was a simple but powerful graphical tool to describe the dynamics of a system.

Activation, self-management, engagement, and retention in behavioral health care: a randomized clinical trial of the DECIDE intervention.

IMPORTANCE: Given minority patients' unequal access to quality care, patient activation and self-management strategies have been suggested as a promising approach to improving mental health care. OBJECTIVE: To determine whether the DECIDE (Decide the problem; Explore the questions; Closed or open-ended questions; Identify the who, why, or how of the problem; Direct questions to your health care professional; Enjoy a shared solution) intervention, an educational strategy that teaches patients to ask questions and make collaborative decisions with their health care professional, improves patient activation and self-management, as well as engagement and retention in behavioral health care. DESIGN, SETTING, AND PATIENTS: In this multisite randomized clinical trial performed from February 1, 2009, through October 9, 2011 (date of last follow-up interview), we recruited 647 English- or Spanish-speaking patients 18 to 70 years old from 13 outpatient community mental health clinics across 5 states and 1 US territory. A total of 722 patients were included in analyses of secondary outcomes. INTERVENTIONS: Three DECIDE training sessions delivered by a care manager vs giving patients a brochure on management of behavioral health. MAIN OUTCOMES AND MEASURES: Primary outcomes were patient assessment of activation (Patient Activation Scale) and self-management (Perceived Efficacy in Patient-Physician Interactions). Secondary outcomes included patient engagement (proportion of visits attended of those scheduled) and retention (attending at least 4 visits in the 6 months after the baseline research assessment), collected through medical record review or electronic records. RESULTS: Patients assigned to DECIDE reported significant increases in activation (mean ß = 1.74, SD = 0.58; P = .003) and self-management (mean ß = 2.42, SD = 0.90; P = .008) relative to control patients, but there was no evidence of an effect on engagement or retention in care. CONCLUSIONS AND RELEVANCE: The DECIDE intervention appears to help patients learn to effectively ask questions and participate in decisions about their behavioral health care, but a health care professional component might be needed to augment engagement in care. DECIDE appears to have promise as a strategy for changing the role of minority patients in behavioral health care. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01226329

Using a discrete choice experiment to elicit time trade-off and willingness-to-pay amounts for influenza health-related quality of life at different ages.

BACKGROUND: Recent research suggests that values for health-related quality of life may vary with the age of the patient. Traditional health state valuation questions and discrete choice experiments are two approaches that could be used to value health. OBJECTIVE: To measure whether public values for health vary with the age of the affected individual. METHODS: A discrete choice experiment was administered via the Internet in December 2007 to measure preferences for different attributes of influenza-related health-related quality of life: age of hypothetical affected individual (range 1-85 years), length of episode (days of illness), severity of illness (workdays lost) and time trade-off or willingness-to-pay amounts. Each respondent answered identical choice questions for a hypothetical family member and for himself/herself. Data on sociodemographic characteristics and influenza illness experience were also collected. Respondents were US adults randomly sampled from an Internet survey panel (n = 1,012). The relative value of attributes was estimated using generalized estimating equations and controlling for sociodemographic characteristics and illness experience. Marginal time traded and marginal willingness to pay using discrete choice and traditional time trade-off or willingness-to-pay questions were compared. RESULTS: Respondents preferred shorter influenza episodes but did not significantly prefer fewer workdays lost if episode length was held constant. Respondents were more likely to choose to avert uncomplicated illness in children and less likely to choose to avert uncomplicated illness in working-age adults. Marginal time trade-off and willingness-to-pay amounts elicited using discrete choice questions were larger than those elicited using direct valuation questions. CONCLUSIONS: Approaches that assume values for health-related quality of life do not vary with the age of a patient may bias economic analyses that use these values. If patient age could affect valuations, then age should be included in the valuation exercise. Additional research should evaluate the effect of patient age on values for other conditions.

Epistatic association mapping in homozygous crop cultivars.

The genetic dissection of complex traits plays a crucial role in crop breeding. However, genetic analysis and crop breeding have heretofore been performed separately. In this study, we designed a new approach that integrates epistatic association analysis in crop cultivars with breeding by design. First, we proposed an epistatic association mapping (EAM) approach in homozygous crop cultivars. The phenotypic values of complex traits, along with molecular marker information, were used to perform EAM. In our EAM, all the main-effect quantitative trait loci (QTLs), environmental effects, QTL-by-environment interactions and QTL-by-QTL interactions were included in a full model and estimated by empirical Bayes approach. A series of Monte Carlo simulations was performed to confirm the reliability of the new method. Next, the information from all detected QTLs was used to mine novel alleles for each locus and to design elite cross combination. Finally, the new approach was adopted to dissect the genetic basis of seed length in 215 soybean cultivars obtained, by stratified random sampling, from 6 geographic ecotypes in China. As a result, 19 main-effect QTLs and 3 epistatic QTLs were identified, more than 10 novel alleles were mined and 3 elite parental combinations, such as Daqingdou and Zhengzhou790034, were predicted.

Valuing health across the lifespan: health state preferences for seasonal influenza illnesses in patients of different ages.

OBJECTIVE: This study sought to measure whether public values for health states vary with the age of the affected individual. METHODS: Health state preferences were measured via a 15-minute survey administered through the Internet in December 2007 using a probability sample of the adult population of the United States (N = 1012). Respondents were asked to value hypothetical descriptions of seasonal influenza illness (uncomplicated influenza illness, hospitalization) and possible vaccine-related adverse events (anaphylaxis, Guillain-Barré syndrome) using time trade-off or willingness-to-pay questions. Respondents were randomized to four different ages for an affected hypothetical individual: 1-year-old, 8-year-old, 35-year-old, 85-year-old. All other aspects of the health state description were held constant. Summary statistics for each health state and age were calculated. The Kruskal-Wallis test was used to measure differences in responses across ages of affected individuals in the hypothetical scenarios. Regression analyses were used to evaluate the effect of age on time trade-off or willingness-to-pay amounts controlling for respondent characteristics. RESULTS: Median values for time trade-off and willingness-to-pay were highest for young children. This pattern was generally consistent across responses and type of valuation. CONCLUSIONS: Approaches that assume health state values do not differ with the age of a patient may bias economic analyses that use these values. If patient age is likely to affect health state valuations, then age should be included as an attribute in the valuation exercise.

Improving diabetes care among patients overdue for recommended testing: a randomized controlled trial of automated telephone outreach.

OBJECTIVE: The study's objective was to assess the effects of automated telephone outreach with speech recognition (ATO-SR) on diabetes-related testing. RESEARCH DESIGN AND METHODS: We identified 1,200 health plan members who were overdue for diabetes-related testing and randomly allocated 600 to ATO-SR and 600 to usual care (no intervention). The intervention included three interactive calls encouraging recommended testing. The primary outcome was retinopathy testing, since this was the health plan's principal goal. Tests for glycemia, hyperlipidemia, and nephropathy were secondary outcomes. RESULTS: In total, 232 participants (39%) verbally responded to the calls. There was no difference between the intervention and the usual care groups in the primary outcome (adjusted hazard ratio 0.93 [95% CI 0.71-1.22]) and no effect of the intervention on any of the secondary outcomes. CONCLUSIONS: Fewer than 40% of the patients randomized to ATO-SR interacted verbally with the system. The intervention had no effect on the study's outcomes.

Development of effective photoplethysmographic measurement techniques: from contact to non-contact and from point to imaging.

This paper provides an overview of the most recent developments in photoplethysmography (PPG). Existing contact point measurement techniques, i.e. pulse oximetry probes, are contrasted with the next generation non-contact and imaging implementations, i.e. non-contact reflection and camera-based PPG. The development of effective PPG monitoring techniques relies on novel approaches to opto-physiological modeling.

An assessment of the safety of adolescent and adult tetanus-diphtheria-acellular pertussis (Tdap) vaccine, using active surveillance for adverse events in the Vaccine Safety Datalink.

Using a new sequential analytic method, the safety of tetanus-diphtheria-acellular pertussis (Tdap) vaccine was monitored weekly among subjects aged 10-64 years during 2005-2008. Encephalopathy-encephalitis-meningitis, paralytic syndromes, seizures, cranial nerve disorders, and Guillain-Barré syndrome were selected as outcomes based on previous reports and biologic plausibility. The risk following Tdap was not significantly higher than the risk after Td. Statistical power was sufficient to detect a relative risk of 4-5 for Guillain-Barré syndrome and 1.5-2 for the other outcomes. This study provides reassurance that Tdap is similar in safety to Td regarding the outcomes studied and supports the viability of sequential analysis for post-licensure vaccine safety monitoring.

[Municipal wastewater treatment using a composite flocculant made of polyaluminum chloride and polydimethyldiallyammonium chloride].

A composite flocculant (denoted JYF-1), made of polyaluminum chloride (PAC) and polydimethyldiallyammonium chloride (PDMDAAC), was used in jar-tests to simulate the chemically enhanced primary treatment (CEPT) for municipal wastewater. Removal of particles, organic compounds, nitrogen and phosphorus in wastewater was investigated, and the effects of pH and surface overflow rate (SOR) on flocculation were also examined. Electrical charge and distribution of particles in wastewater were analyzed before and after flocculation. Furthermore, the flocculation mechanism and application of JYF-1 in CEPT were discussed. The results demonstrate that JYF-1 performs better than PAC under a wide pH and SOR range. When 8 mg x L(-1) JYF-1 is added, 76.72% COD and 64.31% soluble COD (SCOD) can be removed. About 90% soluble TP (STP), 80% TP and 20% TN can be removed by addition of 12 mg x L(-1) JYF-1. After flocculation, the BOD/COD ratio increases from 0.23 to 0.53, which indicates the biodegradation ability of wastewater is improved. It can be concluded that JYF-1 is a high-efficiency low-cost flocculant, which can improve outlet water quality and produce less sludge without changing the existing equipments and treating process in sewage plants.