The combination therapy of isomucronulatol 7-O-beta-glucoside (IMG) and CEP-9722 targeting ferroptosis-related biomarkers in non-small cell lung cancer (NSCLC).

BACKGROUND: NSCLC is a malignant tumor with a high incidence. Ferroptosis presents an essential function in regulating carcinogenesis and tumor progression. However, the ferroptosis-associated prognostic model based on single-cell sequencing of NSCLC remains unexplored. Our study aims to establish a potential predictive model for NSCLC patients and provide available targeted drugs for clinical treatment. METHODS: The data on NSCLC patients were collected from TCGA and GEO databases to analyze their gene expression profiles. ConsensusCluster was adopted to divide the patients into different groups based on ferroptosis-related genes. Then, the univariable Cox and LASSO analyses were applied to data analysis and model establishment. Single-cell analysis was used to explore the risk score genes in different cell populations and states. The protein levels of these genes were also investigated through the HPA database. Drug sensitivity was evaluated in CellMiner database. CCK8 and colony formation assays were performed to validate potential drugs' effects on lung cancer cell lines. RESULTS: A ferroptosis-related prognostic model involving 14 genes in NSCLC patients was established. The risk score model was developed in training set GSE31210 and validated in the test set TCGA. The low-risk score group showed a better prognosis than the high-risk score group. The single-cell analysis revealed that the risk score genes were mainly derived from lung tumor cells. Most risk score genes were more highly expressed in tumor tissue than in normal tissue, according to the HPA database. Besides, these genes were associated with 106 drugs in CellMiner database. Finally, the drug effects on NSCLC cell growth were evaluated by cck8 and colony formation. CONCLUSIONS: We identified an effective ferroptosis-related prognostic model based on single-cell sequencing. The potential prediction model is devoted to exploring clinical therapeutic targets for NSCLC.

A novel life cycle assessment and life cycle costing framework for carbon fibre-reinforced composite materials in the aviation industry.

Purpose: Carbon fibre-reinforced composite materials offer superior mechanical properties and lower weight than conventional metal products. However, relatively, little is known about the environmental impacts and economic costs associated with composite products displacing conventional metal products. The purpose of this study is to develop an integrated life cycle assessment and life cycle costing framework for composite materials in the aviation industry. Methods: An integrated life cycle assessment (LCA) and life cycle costing (LCC) framework has been developed. The displacement of a conventional aluminium door for an aircraft by a composite door is presented as an example of the use of this framework. A graphical visualisation tool is proposed to model the integrated environmental and economic performances of this displacement. LCA and LCC models for composite applications are developed accordingly. The environmental hotspots are identified, and the sensitivity of the environmental impact results to the different composite waste treatment routes is performed. Subsequently, the research suggests a learning curve to analyse the unit price for competitive mass production. Sensitivity analysis and Monte Carlo simulation have been applied to demonstrate the cost result changes caused by data uncertainty. Results: Energy consumption was the hotspot, and the choice of composite waste treatment routes had a negligible effect on the LCA outcomes. Concerning the costs, the most significant cost contribution for the unit door production was labour. The future door production cost was decreased by about 29% based on the learning curve theory. The uncertainties associated with the variables could lead to variations in the production cost of up to about 16%. The comparison between the two doors shows that the composite door had higher potential environmental impacts and cost compared to the conventional aluminium door during the production stage. However, the composite door would have better environmental and financial performance if a weight reduction of 47% was achieved in future designs. Conclusions: The proposed framework and relevant analysis models were applied through a case study in the aerospace industry, creating a site-specific database for the community to support material selection and product development. The graphical tool was proved to be useful in representing a graphical visualisation comparison based on the integration of the LCA and LCC results of potential modifications to the composite door against the reference door, providing understandable information to the decision-makers. Supplementary Information: The online version contains supplementary material available at 10.1007/s11367-023-02164-y.

Anti-inflammatory and immunomodulatory effects of the extracellular vesicles derived from human umbilical cord mesenchymal stem cells on osteoarthritis via M2 macrophages.

Osteoarthritis (OA) is a degenerative illness that greatly impacts the life quality of patients. Currently, the therapeutic approaches for OA are very limited in clinical. The extracellular vesicles (EVs) derived from different mesenchymal stem cells displayed a prominent therapeutic effect on OA. But most EVs have limited resources and the risks of host rejection, immunological response, and etc. Human umbilical cord mesenchymal stem cells (hUCMSCs) hold the advantages of easy availability, minimal immune rejection, and excellent immunomodulatory effects, although hUCMSCs-EVs have seldom been applied in OA. Herein, we investigated the potential immunomodulatory and anti-inflammatory effects of hUCMSCs-EVs on the treatment of OA. In our results, the treatment of hUCMSCs-EVs promoted the polarization of M2-type macrophages and the expression of anti-inflammation-related cytokines (IL-10). Notably, the supernate of M2 macrophages induced by hUCMSCs-EVs inhibited the level of inflammation-associated factors in OA chondrocytes caused by IL-1ß. Further, injection of hUCMSCs-EVs in the articular lumen ameliorated progression of OA and exerted chondroprotective potential based on the OA joint model created by the surgical transection of the anterior cruciate ligament (ACLT). In addition, we found five highly enriched miRNAs in hUCMSCs-EVs, including has-miR-122-5p, has-miR-148a-3p, has-miR-486-5p, has-miR-let-7a-5p, and has-miR-100-5p by High-throughput sequencing of miRNAs, with targeted genes mainly enriched in the PI3K-Akt signaling pathway. Furthermore, we also detected the protein abundance of hUCMSCs-EVs using liquidation chromatography with tandem quadrupole mass spectrometry (LC-MS/MS) analysis. Thus, our study indicates that hUCMSCs-EVs can alleviate cartilage degradation during the OA progression, mechanically may through delivering key proteins and modulating the PI3K-Akt signaling pathway mediated by miRNAs to promote polarization of M2 macrophage, exhibiting potent immunomodulatory potential. The current findings suggest that hUCMSCs-EVs might serve as a new reagent for the therapy of OA.

Long-term survival of nasopharyngeal carcinoma patients with Stage II in intensity-modulated radiation therapy era.

OBJECTIVES: To evaluate the long-term survival and the role of chemotherapy in nasopharyngeal carcinoma (NPC) patients in Stage II treated by intensity-modulated radiation therapy (IMRT). METHODS: Three hundred and eleven NPC patients in Stage II were reviewed. All were treated with IMRT with or without chemotherapy, with 191, 20 and 100 patients being defined as T1N1M0, T2N0M0 and T2N1M0 stage, respectively. RESULTS: At a median follow-up of 57 months, the 5-year overall survival, disease-specific survival, distant metastasis-free survival, loco-regional relapse-free survival (LRRFS) and progression-free survival were 91.1, 93.5, 90.6, 95.9 and 87.6%, respectively. T2N1 patients had significant poorer survival outcomes than T1N1 patients, with T2N0 patients in between. Further analysis showed that the addition of chemotherapy could only improve LRRFS [hazard ratio (HR) 0.263, 95% confidence interval (CI) 0.083-0.839, P = 0.024], especially for T1N1 patients (HR 0.209, 95% CI 0.046-0.954, P = 0.043). For those in the T2N1M0 group, chemotherapy, as used in our series, added no benefit to any endpoint. CONCLUSIONS: IMRT in NPC patients in Stage II was quite therapeutic; however, different subgroups have distinct survival outcomes. Distant metastasis was the main failure pattern, especially for those with T2N1 disease, and the chemotherapy currently in use failed to treat subclinical metastatic foci effectively. Further prospective study is warranted to find out the role and the optimal schedule of chemotherapy in this subgroup of patients.

Geothermal Energy Impact Estimator: A software application for estimating the life-cycle environmental impacts of geothermal energy.

Geothermal energy is a renewable source of base-load power that is expected to play an important role in the transition to a low-carbon economy. In this article, we introduce a novel software application - named Geothermal Energy Impact Estimator - which computes the environmental impacts, including carbon emissions, of existing or future geothermal plants, using the Life Cycle Assessment (LCA) methodology. The software application is user-friendly and was designed to be used by geothermal companies and policy makers. We provide two specific use cases of the software application that represent existing plants in Iceland and in the UK.

Hsa_circ_0007031 promotes the proliferation and migration of osteosarcoma cells by sponging miR-196a-5p to regulate the HOXB6.

Circular RNAs (circRNAs), a subclass of noncoding RNAs, have been demonstrated to play an essential role in osteosarcoma (OS) development. However, there is still a significant gap in investigating its biological functions and underlying molecular mechanisms, and novel targets of circRNAs have yet to be fully explored. Herein, we found that hsa_circ_0007031 is noticeably raised in OS clinical tissues and cell lines. Hsa_circ_0007031 accelerates OS cell proliferation and migration in vitro and tumor growth and metastasis in vivo and is strongly linked with the stemness of cancer stem cells in OS. Mechanistically, hsa_circ_0007031 shares miRNA response elements with Homeobox B6 (HOXB6), which is identified as a novel pro-tumorigenic gene of OS. Hsa_circ_0007031 competitively binds to miR-196a-5p to prevent miR-196a-5p from lowering the level of HOXB6, which modulates chemokines of cytokine-cytokine receptor interaction signaling pathway and finally promotes OS malignant behavior. In summary, our data unveiled that hsa_circ_0007031/miR-196a-5p/HOXB6 axis-mediated cytokine-cytokine receptor interaction facilitates the progression of OS and maintains the properties of tumor stem cells, which could be a promising therapeutic target for OS.

The Prevalence and Death Risk of Male Breast Cancer: A Study Based on the Surveillance, Epidemiology, and End Results Database.

This study was to investigate the prevalence and death risk of male breast cancer (MBC) patients. The prevalence trend was based on the Surveillance, Epidemiology, and End Results (SEER) database from 1975 to 2017. A competitive risk analysis was performed to analyze the death risk of MBC patients. Hazard ratio (HR) and 95% confidence intervals (CIs) were calculated. The results indicated that the prevalence of MBC after the standardization of the total population increased in 1975-2017 and its annual percentage change (APC) was 0.536% (95% CI = [0.362%, 0.713%]). The prevalence of MBC was rapidly increased in patients aged ≥70 years (APC = 0.780%; 95% CI = [0.491%, 1.076%]) and Grade Ⅱ tumors (APC = 1.462%; 95% CI = [1.260%, 1.686%]). The 1-, 3-, and 5-year cumulative mortality of MBC patients who died of MBC was 2.23% (95% CI = [1.61%, 2.85%]), 7.56% (95% CI = [6.33%, 8.78%]), and 13.10% (95% CI = [11.10%, 11.32%]), respectively. Competitive risk analysis demonstrated that Blacks (HR = 1.76; 95% CI = [1.12, 2.77]), Grade 3 (HR = 2.56; 95% CI = [1.03, 6.35]), AJCC (American Joint Committee on Cancer) Stage Ⅲ (HR = 3.04; 95% CI = [1.76, 5.26]), and AJCC Stage Ⅳ (HR = 7.27; 95% CI = [1.36, 38.83]) were associated with an increased MBC-specific death risk, whereas married status (HR = 0.40; 95% CI = [0.25, 0.64]), surgery (HR = 0.25; 95% CI = [0.12, 0.50]), Luminal A subtype (HR = 0.20; 95% CI = [0.07, 0.53]), and Luminal B subtype (HR = 0.29; 95% CI = [0.10, 0.87]) were related to a reduced MBC-specific death risk. In addition, similar results can be observed in patients with surgery recommended and done (p < .05). This study may provide evidence for the prevalence trend, cumulative mortality, and death risk of MBC patients.

Effect of low-dose lanthanum carbonate on calcium and phosphorus metabolism in Asian Patients with end-stage renal disease, maintenance hemodialysis and hyperphosphatemia.

Objective: This study aimed to examine whether a 12-week small-dose lanthanum carbonate (LaCO3; 500 mg/d) treatment could improve calcium and phosphorus metabolism and parathyroid function in Asian patients with end-stage renal disease (ESRD) under hemodialysis. Methods: This was a prospective observational study of patients treated at our Hospital between 10/2014 and 02/2015. The patients were given 500 mg/d of LaCO3 with lunch for 12 weeks. Results: Baseline and after 12-week treatment serum phosphorus levels were 2.49±0.51 mmol/L and 1.65±0.34 mmol/L (P<0.001). The baseline and after 12-week treatment calcium×phosphorus product were 69.40±17.34 mg2/dL2 and 44.27±9.67 mg2/dL2 (P<0.001). There was no significant difference in serum calcium and iPTH levels from baseline to after 12 weeks treatment (both P>0.05). Fourteen (25.9%) patients developed gastrointestinal adverse reactions to LaCO3 and 10 patients improved after treatment. Conclusion: Far below the 1.5-3.0g/d required by the drug instructions, LaCO3 500 mg/d for 12 weeks can still reduce serum phosphorus level and calcium × phosphorus product, without serum calcium and iPTH levels increase.

Identification of Candidate MicroRNA-mRNA Subnetwork for Predicting the Osteosarcoma Progression by Bioinformatics Analysis.

Osteosarcoma (OS) is the pretty common primary cancer of the bone among the malignancies in adolescents. A single molecular component or a limited number of molecules is insufficient as a predictive biomarker of OS progression. Hence, it is necessary to find novel network biomarkers to improve the prediction and therapeutic effect for OS. Here, we identified 230 DE-miRNAs and 821 DE-mRNAs through two miRNA expression-profiling datasets and three mRNA expression-profiling datasets. We found that hsa-miR-494 is closely linked with the survival of OS patients. In addition, we analyzed GO and KEGG enrichment for targets of hsa-miR-494-5p and hsa-miR-494-3p through R programming. And five mRNAs were predicted as common targets of hsa-miR-494-5p and hsa-miR-494-3p. We further revealed that upregulated TRPS1 was strongly correlated with poor outcomes in OS patients through the survival analysis based on the TARGET database. The qRT-PCR study verified that the expression of hsa-miR-494-5p and hsa-miR-494-3p was declined considerably, while TRPS1 was notably raised in OS cells when compared to the osteoblasts. Thus, we generated a new regulatory subnetwork of key miRNAs and target mRNAs using Cytoscape software. These results indicate that the novel miRNA-mRNA subnetwork composed of hsa-miR-494-5p, hsa-miR-494-3p, and TRPS1 might be a characteristic molecule for assessing the prognostic value of OS patients.

Analysis and identification of m6A RNA methylation regulators in metastatic osteosarcoma.

Osteosarcoma (OS) is characterized by rapid growth and early metastasis. However, its mechanism remains unclear. N6-methyladenosine (m6A) modification and its regulatory factors play essential roles in most cancers, including OS. In this study, we screened out 21 m6A modifiers using the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database, followed by the identification of the critical m6A methylation modifiers. The results revealed that the expression levels of three m6A methylation regulators, namely RBM15, METTL3, and LRPPRC, were associated with the low survival rate of patients with OS. We further studied the independent prognostic factors by performing univariate and multivariate Cox analyses and found that metastasis was an independent prognostic factor for patients with OS. Furthermore, we found for the first time that RBM15 was specific for metastatic OS rather than non-metastatic OS. Moreover, the significant overexpression of RBM15 was validated in metastatic OS cell lines and in actual human clinical specimens. We also revealed that RBM15 promoted the invasion, migration, and metastasis of OS cells through loss-functional and gain-functional experiments and an animal metastatic model. In conclusion, RBM15 has a high correlation with OS metastasis formation and the decreased survival rate of patients with OS, and this may serve as a useful biomarker for predicting metastasis and prognosis of patients with OS.

Prognostic Implications of the Complement Protein C1Q and Its Correlation with Immune Infiltrates in Osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most widespread bone tumour among childhood cancers, and distant metastasis is the dominant factor in poor prognosis for patients with OS. Therefore, it is necessary to identify new prognostic biomarkers for identifying patients with aggressive disease. METHODS: Two OS datasets (GSE21257 and GSE33383) were downloaded from the Gene Expression Omnibus (GEO) and subsequently subjected to weighted gene co-expression network analysis (WGCNA) and differential gene expression analysis (DGE) to screen candidate genes. A prognostic model was constructed using OS data derived from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) program to further screen key genes and perform gene ontology (GO) analysis. The prognostic values of key genes were assessed using the Kaplan-Meier (KM) plotter. The GEO dataset was used for immune infiltration analysis and association analysis of key genes. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) was employed to validate the expression levels of potentially crucial genes in OS cell lines. RESULTS: In the present study, we found 114 genes with a highly significant correlation in the module and 44 downregulated genes; 25 candidate genes overlapped in the two parts of the genes. Among these, three key genes, C1QA, C1QB, and C1QC, were the most significant hub genes, which had the highest node degrees, were clustered into one group, and implicated in most significant biological processes (regulation of immune effector process). Moreover, these three key genes were negatively associated with the prognosis of OS and positively associated with three immune cells (follicular helper T cells, memory B cells, and CD8 T cells). Additionally, compared to non-metastatic OS cell lines, the expression of three key genes was significantly downregulated in metastatic OS cell lines. CONCLUSION: Our results revealed that three key genes (C1QA, C1QB, and C1QC) were implicated in tumour immune infiltration and may be promising biomarkers for predicting metastasis and prognosis of patients with OS.

Super-Anticoagulant Heparin-Mimicking Hydrogel Thin Film Attached Substrate Surfaces to Improve Hemocompatibility.

In this study, heparin-mimicking hydrogel thin films are covalently attached onto poly(ether sulfone) membrane surfaces to improve anticoagulant property. The hydrogel films display honeycomb-like porous structure with well controlled thickness and show long-term stability. After immobilizing the hydrogel films, the membranes show excellent anticoagulant property confirmed by the activated partial thromboplastin time values exceeding 600 s. Meanwhile, the thrombin time values increase from 20 to 61 s as the sodium allysulfonate proportions increase from 0 to 80 mol%. In vitro investigations of protein adsorption and blood-related complement activation also confirm that the membranes exhibit super-anticoagulant property. Furthermore, gentamycin sulfate is loaded into the hydrogel films, and the released drug shows significant inhibition toward E. coli bacteria. It is believed that the surface attached heparin-mimicking hydrogel thin films may show high potential for the applications in various biological fields, such as blood contacting materials and drug loading materials.

Locoregionally advanced nasopharyngeal carcinoma in childhood and adolescence: Analysis of 95 patients treated with combined chemotherapy and intensity-modulated radiotherapy.

BACKGROUND: The purpose of this study was to evaluate the treatment outcomes and toxicities of intensity-modulated radiation therapy (IMRT) for children and adolescents with locoregionally advanced nasopharyngeal carcinoma (NPC). METHODS: Ninety-five patients of <25 years old in locoregionally advanced NPC (stage III-IVB) were analyzed. All were given neoadjuvant chemotherapy followed by IMRT with or without concurrent chemotherapy/adjuvant chemotherapy. RESULTS: The 4-year overall survival (OS), locoregional relapse-free survival, progression-free survival (PFS), and distant metastasis-free survival (DMFS) were 90.8%, 94.9%, 79.1%, and 84.0%, respectively. N classification was the only significant predicting factor for OS, PFS, and DMFS, with the p value of .017, .015, and 0.054, respectively. The main long-term complications were xerostomia, hearing impairment, and neck fibrosis. CONCLUSION: Neoadjuvant chemotherapy followed by IMRT with or without concurrent/adjuvant chemotherapy produced a superb treatment outcome in children and adolescents with stage III to IVB disease. Distant metastasis was the main failure. More effective treatment strategies are urgently needed to further improve the long-term survival. © 2015 Wiley Periodicals, Inc. Head Neck 38: E665-E672, 2016.

Prognostic Evaluation of Nasopharyngeal Carcinoma with Bone-Only Metastasis after Therapy.

PURPOSE: To evaluate the prognosis of nasopharyngeal carcinoma (NPC) patients who developed bone-only metastasis after primary treatment and the stratification of these patients into different risk groups based on independent prognostic factors. MATERIALS AND METHODS: Eighty NPC patients who developed bone-only metastasis after definitive radiotherapy from October 2005 to December 2010 were enrolled. All these patients received palliative treatment for bone metastasis, including chemotherapy and/or radiotherapy. Clinical features, treatment modality, and laboratory parameters were examined with univariate and multivariate analyses. RESULTS: The median follow-up time was 15.5 months (range, 2-67 months) for the whole cohort. The median overall metastatic survival (OMS) time and the 2-year estimate OMS rate were 26.5 months and 52%, respectively. Multivariate analysis indicated that patients with short metastases-free interval, multiple bone metastases sites, high serum lactic dehydrogenase levels, and treated with radiotherapy or chemotherapy alone had significantly worse outcomes. Patients were stratified into three different risk groups based on the number of adverse factors present. The OMS curves of the three groups were all significantly different (p<0.001). CONCLUSION: Severl prognostic factors were found to be associated with worse outcomes. According to the number of adverse factors present, bone-only metastasis patients can be stratified into three risk groups with significantly different prognoses. Such grouping may help in improving the design of clinical trials and in guiding individualized treatment for NPC patients with bone-only metastasis.

Suggestions for lymph node classification of UICC/AJCC staging system: a retrospective study based on 1197 nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy.

This article provides suggestions for N classification of Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system of nasopharyngeal carcinoma (NPC), purely based on magnetic resonance imaging (MRI) in intensity-modulated radiation therapy (IMRT) era.A total of 1197 nonmetastatic NPC patients treated with IMRT were enrolled, and all were scanned by MRI at nasopharynx and neck before treatment. MRI-based nodal variables including level, laterality, maximal axial diameter (MAD), extracapsular spread (ECS), and necrosis were analyzed as potential prognostic factors. Modifications of N classification were then proposed and verified.Only nodal level and laterality were considered to be significant variables affecting the treatment outcome. N classification was thus proposed accordingly: N0, no regional lymph node (LN) metastasis; N1, retropharyngeal LNs involvement (regardless of laterality), and/or unilateral levels I, II, III, and/or Va involvement; N2, bilateral levels I, II, III, and/or Va involvement; and N3, levels IV, Vb, and Vc involvement. This proposal showed significant predicting value in multivariate analysis. N3 patients indicated relatively inferior overall survival (OS) and distant metastasis-free survival (DMFS) than N2 patients; however, the difference showed no statistical significance (P = 0.673 and 0.265 for OS and DMFS, respectively), and this was considered to be correlated with the small sample sizes of N3 patients (79 patients, 6.6%).Nodal level and laterality, but not MAD, ECS, and necrosis, were considered to be significant predicting factors for NPC. The proposed N classification was proved to be powerfully predictive in our cohort; however, treatment outcome of the proposed N2 and N3 patients could not differ significantly from each other. This insignificance may be because of the small sample sizes of N3 patients. Our results are based on a single-center data, to develop a new N classification that is universally acceptable; further verification by data from multicenter is warranted.

Survival analyses correlate stanniocalcin 2 overexpression to poor prognosis of nasopharyngeal carcinomas.

BACKGROUND: Stanniocalcin 2 (STC2) is overexpressed in several types of human cancers, and its overexpression positively correlates to tumor progression and poor prognosis. However, the clinical significance of STC2 overexpression in nasopharyngeal carcinomas (NPC) has not been investigated. This study examined STC2 expression in a cohort of 94 NPC samples, and explored its value in clinical diagnosis and prognosis. METHODS: Tumor samples from 94 patients diagnosed in 2008 were studied. All samples were obtained prior to treatment start. All cases were clinically diagnosed and pathologically confirmed to be poorly differentiated or undifferentiated NPC without distant metastasis, and have been treated with radical radiation therapy and followed-up for five years. Survival analyses were performed. RESULTS: Of the 94 NPC samples, STC2 overexpression (STC2+) was detected in 65 samples (69.1%). Overall survival rate of STC2 (+) patients is significantly lower than that of patients with normal STC2 levels (72.2% vs. 96.4%, respectively, P = 0.049). Moreover, STC2 (+) is also strongly predictive of a low progression-free survival and distant metastasis-free survival (63.0% vs 92.9%. P = 0.007; and 77.0% vs 96.4%. P = 0.028). Of the 54 patients treated with IMRT, residual tumors were found in 54.8% of STC2 positive patients (17/31), but only in 17.4% of STC2 negative ones (4/23), suggesting STC2 overexpression predicts a higher risk of residual tumors after IMRT. CONCLUSIONS: STC2 overexpression correlates to poor prognosis for NPC and may be useful as a novel biomarker to predict NPC responses to radiation. Whether STC2 promotes NPC progression and metastasis remains to be investigated.

Electrochemical disinfection of Escherichia coli in the presence and absence of primary sludge particulates.

Electrochemical (EC) residual disinfection of Escherichia coli (E. coli) in the presence and absence of primary sludge particulates (PSPs) was studied. The kinetics followed a first-order rate law. When PSPs were absent, the EC residual disinfection rate coefficient (k) increased linearly with EC pretreatment energy (EC, 0-0.63 kWh/m(3)). However, with 143 mg PSPs/L, k first increased linearly with EC (0-0.28 kWh/m(3)) and then decreased linearly with EC (0.28-0.42 kWh/m(3)). H2O2 was detected during EC pretreatment in PSPs-free samples and the H2O2 concentration (CH) increased with EC (0-0.83 kWh/m(3)) linearly. Chloride was detected in PSPs aqueous samples (143 mg PSPs/L) and its concentration (CC) changed during EC pretreatment: initially, a decrease of CC was observed when EC increased from 0 to 0.28 kWh/m(3), followed by an increase of CC when EC increased 0.28-0.42 kWh/m(3). In both cases, k correlated to the initial post-EC chloride concentration (CCI) in an inverse linear relationship. This two-stage change of CC and k was caused by a combination of two reactions: anodic oxidation of chloride and the reaction of chloramines with excess chlorine. This paper explains the mechanisms underlying EC residual disinfection in the presence and absence of PSPs, and proposes a feasible strategy for EC disinfection when PSPs are present, an approach that could be useful in the treatment of combined sewage overflow (CSO).

Effects of primary sludge particulate (PSP) entrapment on ultrasonic (20 kHz) disinfection of Escherichia coli.

The role of primary sludge particulates (PSPs) in ultrasonic disinfection of Escherichia coli (E. coli) was investigated. Entrapment of E. coli by PSP was directly observed through scanning electron microscope (SEM) after E. coli and PSP were incubated together in water for 24 h at 35 °C. Entrapment coefficient was proposed for the first time to reflect the ability of PSP to entrap E. coli and was estimated as 1.4 × 10(3) CFU/mg PSP under our experimental conditions. Ultrasonication (20 kHz) of different E. coli-PSPs solutions showed that the entrapped E. coli cells were protected by PSP from ultrasonication and the unentrapped cells were not. However, the protection of entrapped E. coli cells gradually decreased as ultrasonication proceeded, suggesting the ability of power ultrasonication to deprotect the entrapped E. coli cells. SEM studies suggested a two-step mechanism for ultrasonic (20 kHz) disinfection of entrapped E. coli: breakdown of the protective PSP refugia and disinfection of the exposed E. coli cells. This research will enable more informed decisions about disinfection of aqueous samples where porous PSP are present.