Evidence-Based Framework to Manage Cyanobacteria and Cyanotoxins in Water and Sludge from Drinking Water Treatment Plants

Freshwater bodies and, consequently, drinking water treatment plants (DWTPs) sources are increasingly facing toxic cyanobacterial blooms. Even though conventional treatment processes including coagulation, flocculation, sedimentation, and filtration can control cyanobacteria and cell-bound cyanotoxins, these processes may encounter challenges such as inefficient removal of dissolved metabolites and cyanobacterial cell breakthrough. Furthermore, conventional treatment processes may lead to the accumulation of cyanobacteria cells and cyanotoxins in sludge. Pre-oxidation can enhance coagulation efficiency as it provides the first barrier against cyanobacteria and cyanotoxins and it decreases cell accumulation in DWTP sludge. This critical review aims to: (i) evaluate the state of the science of cyanobacteria and cyanotoxin management throughout DWTPs, as well as their associated sludge, and (ii) develop a decision framework to manage cyanobacteria and cyanotoxins in DWTPs and sludge. The review identified that lab-cultured-based pre-oxidation studies may not represent the real bloom pre-oxidation efficacy. Moreover, the application of a common exposure unit CT (residual concentration × contact time) provides a proper understanding of cyanobacteria pre-oxidation efficiency. Recently, reported challenges on cyanobacterial survival and growth in sludge alongside the cell lysis and cyanotoxin release raised health and technical concerns with regards to sludge storage and sludge supernatant recycling to the head of DWTPs. According to the review, oxidation has not been identified as a feasible option to handle cyanobacterial-laden sludge due to low cell and cyanotoxin removal efficacy. Based on the reviewed literature, a decision framework is proposed to manage cyanobacteria and cyanotoxins and their associated sludge in DWTPs.     

Microstructure Evolution of Al6061 Alloy Made by Additive Friction Stir Deposition

In this paper, the phase structure, composition distribution, grain morphology, and hardness of Al6061 alloy samples made with additive friction stir deposition (AFS-D) were examined. A nearly symmetrical layer-by-layer structure was observed in the cross section (vertical with respect to the fabrication-tool traversing direction) of the as-deposited Al6061 alloy samples made with a back-and-forth AFS-D strategy. Equiaxed grains were observed in the region underneath the fabrication tool, while elongated grains were seen in the “flash region” along the mass flow direction. No clear grain size variance was discovered along the AFS-D build direction except for the last deposited layer. Grains were significantly refined from the feedstock (~163.5 µm) to as-deposited Al6061 alloy parts (~8.5 µm). The hardness of the as-fabricated Al6061 alloy was lower than those of the feedstock and their heat-treated counterparts, which was ascribed to the decreased precipitate content and enlarged precipitate size.     

The relationship between occupational exposure to organic solvents and metabolic syndrome in petroleum refinery workers in Tehran,Iran

AimsThe rising prevalence of metabolic syndrome has made it a major health concern. Chronic occupational exposure to organic solvents affects different systems of the body. This study aimed to investigate the association between exposure to organic solvents and the prevalence of metabolic syndrome in petroleum refinery workers.MethodThis study was conducted in 2019–2020 on workers employed in an Iranian petroleum refinery. The demographic and occupational information on the participants was obtained using the interview method. Their height, weight, and blood pressure were measured by the occupational health team, and fasting blood samples were taken from them to measure the paraclinical parameters.ResultsIn this study, 1009 petroleum refinery workers were analyzed. The prevalence of metabolic syndrome in workers was 20.1% and it was about two times higher in exposed workers (CI 95%: 1.61–3.35) compared to non-exposed ones. Factors associated with the prevalence of metabolic syndrome include age, higher BMI, exercise, and longer exposure to organic solvents.ConclusionFindings of this study suggested that exposure to organic solvents is associated with increased prevalence of metabolic syndrome (the highest association was observed with elevated serum triglycerides). Besides, longer exposure to organic solvents increased the risk of developing metabolic syndrome.     

Impact of serum soluble CD155 level at diagnosis on interim response to CHOP with or without rituximab in diffuse large B cell lymphoma

Clinical and Experimental Medicine - CD155 is frequently overexpressed in human malignant tumors, and it is associated with poor prognosis. The expression of its soluble form (sCD155) as well as...     

Biotransfer of metals to the insect Neochetina eichhornae via aquatic plants

Trace elements are ubiquitously present in the environment occurring naturally in soil and water. However, the present day concern is their increase in the environment due to rapid industrialization. An attempt was made to determine the bioaccumulation of trace elements transferred from the aquatic medium to aquatic plants placed in the experimental medium and subsequently biomagnified through the food chain in insects feeding on the leaves. The biosystem under study was the aquatic plant Eichhornia crassipes (Mart) Solms and their specific feeders Neochetina eichhornae (Warner). The plants exposed to known concentrations of Cd, Zn, Hg, and Mn for one week were fed to the insects and the concentration of metal ions in various parts of the plants and insects was determined by atomic absorption spectroscopy and ICPAES. The rates of uptake of the various metal ions varied, depending upon metal solubility and their affinities to the biosystems. Bioaccummulation in the roots was highest compared to the aerial parts of the plant. This investigation revealed the biotransfer of metals via a simple food chain model which consisted of two trophic levels, from contaminated waters to the insects via the aquatic plants.     

Role of DW-MRI and ADC value in monitoring therapy of head and neck squamous cell carcinoma

Aim

To evaluate role of DW-MRI and ADC value in monitoring therapy of head and neck squamous cell carcinoma (HNSCC).