Combination of chemical coagulation and membrane-based separation for dairy wastewater treatment.

An important factor resulted from the ascension of the milk and milk-based by-products production is many effluents directly released into the environment. The main objective of this study was to evaluate the efficiency of the combination of the chemical coagulation, with ferric chloride as a coagulant, and the membrane separation processes (MSP) and reverse osmosis (RO) processes in the treatment of effluents from a powdered milk dairy industry. To evaluate the effectiveness of the integration of these mechanisms, the characterization of the effluents was carried out through Total Nitrogen (Ntotal), Total Organic Carbon (TOC), Chemical Oxygen Demand (COD), color, pH, and turbidity analysis. Regarding the treatments with ferric chloride, the Ntotal removal was up to 55.7% (concentration of 1.2 g L- 1) and the color up to 50% (0.7 g L- 1). For the MSP and RO treatments, the color removal was up to 100% (1st RO), turbidity up to 100% (1st RO), COD up to 98.7% (3rd RO), and TOC up to 96.7% (3rd RO). Finally, the integration of the chemical coagulation and MSP processes was efficient for the treatment of dairy industry wastewater and provides the return of water in appropriate characteristics according to legislation.

Effect of coagulation on microfibers in laundry wastewater.

Microplastics pollution in the aquatic system has received significant attention due to their recalcitrant nature and ecotoxicological threat. Municipal wastewater typically contains various microplastics with synthetic microfibers as a significant constituent from the laundry process. The fate of microfibers in conventional wastewater processes is not clearly understood. In this study, the effect of coagulation on microfibers obtained from a lint screen of a domestic dryer and resuspended in pure water, and also in laundry wastewater was investigated using ferric chloride and polyaluminum chloride (PACl). The removal efficiency of the microfibers resuspended in pure water varied from 86% to 96% depending on the fiber size ranges: < 90 µm, 90-125 µm, and >125 µm with the smaller size microfibers showing a lower removal efficiency. Surfactant present in detergent in laundry wastewater reduced the microfibers removal efficiency to 0-37%, however, the addition of PACl increased microfibers removal to 90%. The optimal PACl concentrations for ≥90% removal were 1.75, 2, 4, and 6 mg/L for 0.5, 2, 4, 8 mg/L detergent, respectively. Zeta potential, FTIR, and SEM analysis were applied to observe the surface changes of microfibers during coagulation indicating possible mechanisms of coagulation. The dominant mechanisms for coagulation of microfibers by FeCl3 and PACl seem to be charge neutralization and adsorption-bridging. This work provided some insights about the fate of laundry microfibers in primary treatment processes.

Optimization of Coagulation-Flocculation Process in Efficient Arsenic Removal from Highly Contaminated Groundwater by Response Surface Methodology.

Elevated arsenic (As) contamination in water, especially groundwater, has been recognized as a major problem of catastrophic proportions. This work explores As(V) removal via the coagulation-flocculation process by use of ferric chloride coagulant and polyacrylamide k16 co-coagulant as a first time. The effects of major operating variables such as coagulant dosing (50, 125 and 200 mg/L), co-coagulant dosing (5, 12.5 and 20 mg/L), pH (6, 7and 8), fast mixing time (1, 2 and 3 min), and fast mixing speed (110, 200 and 300 rpm) on As(V) removal efficiency were investigated by a Box-Behnken statistical experiment design (BBD) and response surface methodology (RSM). According to factors F values, coagulant dosing, rapid mixing speed, pH, and co-coagulant dosing showed the most effect on As(V) removal efficiency, and the rapid mixing time factor indicated the slightest effect. The proposed quadratic model was significant with a p value < 0.0001 and has satisfactorily described the experimental data with R2 and adjusted R2 values of 0.9855 and 0.9738, respectively. Predicted model optimal conditions with target of complete As(V) removal were coagulant dosing = 197.63 ppm, co-coagulant dosing = 19.55 ppm, pH = 7.37, fast mixing time = 1.43 min and fast mixing speed = 286.77 rpm. The treatment of Nazarabad well water sample with an initial As(V) concentration of 5 mg/L under the optimal conditions removed 100% As(V) with the volume of produced sludge of 10.7 mL/200 mL. Increasing coagulant dosing, co-coagulant dosing, fast mixing time and fast mixing speed operation parameters from low-level to high-level values indicated 78%, 20%, 10.52% and 9.47% increases in volume of the produced sludge, respectively. However, a reduction of 13.63% in volume of the produced sludge resulted via pH increases.

Steering Scholl Oxidative Heterocoupling by Tuning Topology and Electronics for Building Thiananographenes and Their Functional N-/C-Congeners.

While intramolecular Scholl oxidative coupling between two arenes is common, successful C-C heterocoupling between thiophene and arene is scarce. The latter is due to the notorious reactivity of thiophene towards polymerization under oxidative conditions. This report systematically demonstrates how topological variation of electronics and reactivity in thiophene substrates can lead to efficient oxidative heterocoupling. Bis(biaryl)thiophenes having reactive α- and ß-positions open are the choice of substrates. The cyclizing arene partners are so electronically tuned for thiophene's reactivity (at α- and ß-) as to establish C-C bond oxidatively generating symmetrical as well as unsymmetrical diphenanthrothiophenes which are basic thiananographenes. Depending on the cyclizing-couple's electronics, either arene- or thiophene-centered oxidation initiates C-C heterocoupling. The potential utility of these simple thiananographenes is further unfurled by converting them to functional N-/C-graphene segments that are aza-corannulene precursor and tetrabenzospirobifluorene. Their bright emission and extended electrochemical stability are remarkable that may be potentially important and applicable.

Removal of Tannic Acid Stabilizes CuO Nanoparticles from Aqueous Media by PAFC: Effect of Process Conditions and Water Chemistry.

The increased utilization of CuO nanoparticles (CuO NPs) in various fields has raised concerns about their discharge into water containing a wide range of organic ligands. Moreover, the adsorption of these ligands can stabilize the CuO NPs in drinking water treatment plants. Thus, their removal from potable water is important to mitigate the risk to humans. The present study explored the efficacy of the coagulation-sedimentation (C/S) process for the removal of tannic acid (TA)-stabilized CuO NPs using polyaluminum ferric chloride (PAFC) as a coagulant. Moreover, the influence of process conditions (stirring speed) and water chemistry (i.e., pH and ionic strength (IS)) were also investigated to determine their impact on removal. The results showed that stirring speed in the reaction phase significantly affected the removal due to increased flocculation compared with stirring speed in the mixing phase. In addition, pH and IS affect the colloidal stability and removal efficiency of CuO NPs. A relatively better removal performance (<99%) of CuO NPs was found at lower coagulant dosage in the pH range 6-8. The addition of organic ligands reversed the surface charge potential and enhanced the colloidal stability of CuO NPs, resulting in the destabilization of TA-CuO NPs, thereby reducing the optimum PAFC dosage for removal. By contrast, the IS above the critical coagulation concentration decreased the removal efficiency due to inhibition of the ionic activity of PAFC hydrolysate in the aqueous environment. Fourier transform infrared findings of TA-CuO NPs composite flocs suggest that the primary removal mechanism might be mediated via the combined effect of neutralization, complexation as well as adsorption.

Clot Contraction Drives the Translocation of Procoagulant Platelets to Thrombus Surface.

Objective- After activation at the site of vascular injury, platelets differentiate into 2 subpopulations, exhibiting either proaggregatory or procoagulant phenotype. Although the functional role of proaggregatory platelets is well established, the physiological significance of procoagulant platelets, the dynamics of their formation, and spatial distribution in thrombus remain elusive. Approach and Results- Using transmission electron microscopy and fluorescence microscopy of arterial thrombi formed in vivo after ferric chloride-induced injury of carotid artery or mechanical injury of abdominal aorta in mice, we demonstrate that procoagulant platelets are located at the periphery of the formed thrombi. Real-time cell tracking during thrombus formation ex vivo revealed that procoagulant platelets originate from different locations within the thrombus and subsequently translocate towards its periphery. Such redistribution of procoagulant platelets was followed by generation of fibrin at thrombus surface. Using in silico model, we show that the outward translocation of procoagulant platelets can be driven by the contraction of the forming thrombi, which mechanically expels these nonaggregating cells to thrombus periphery. In line with the suggested mechanism, procoagulant platelets failed to translocate and remained inside the thrombi formed ex vivo in blood derived from nonmuscle myosin ( MYH9)-deficient mice. Ring-like distribution of procoagulant platelets and fibrin around the thrombus observed with blood of humans and wild-type mice was not present in thrombi of MYH9-knockout mice, confirming a major role of thrombus contraction in this phenomenon. Conclusions- Contraction of arterial thrombus is responsible for the mechanical extrusion of procoagulant platelets to its periphery, leading to heterogeneous structure of thrombus exterior.

How useful are ferric chloride models of arterial thrombosis?

The ferric chloride models of arterial thrombosis are useful tools with which to investigate the cellular and molecular mechanisms that contribute to arterial thrombosis. Recent insights have, however, revealed the complex and multifaceted mechanism by which ferric chloride induces thrombus formation. Here, we discuss the strengths and weaknesses of the ferric chloride models of arterial thrombosis. Particular focus is given to the phenotypes of different knockout mice in the ferric chloride models and how these compare to other models with independent modes of initiation. Further, we discuss the relevance of the ferric chloride models to the human pathology of atherothrombotic disease.

Effect of ferric chloride on phosphorus immobilization and speciation in Dianchi Lake sediments.

Immobilization of phosphorus in lake sediments and control of internal-loading phosphorus release have become crucial aspects of eutrophication lake management. In this study, the immobilization efficiency of phosphorus by ferric chloride in Dianchi Lake sediments was investigated. In addition, effects of the dosage of ferric chloride and contact time on the release of phosphorus from sediments were investigated. Laboratory experiments revealed that ferric chloride can effectively inhibit the release of phosphorus from sediments. At a ferric chloride dosage of 10 mg/g, the total phosphorus concentration of the overlying water was reduced by ~87%. With the increase in the contact time, the amount of phosphorus immobilized by ferric chloride increased. To further evaluate the feasibility of ferric chloride for immobilising phosphorus in sediments, an amplification experiment with a water volume of 50 L was carried out. By the addition of 6 mg/g of ferric chloride, the total phosphorus concentration of the overlying water was still less than 0.01 mg/L after 100 days. At the same time, the phosphorus species in the sediment after treatment with ferric chloride were analyzed. Results revealed that ferric chloride mainly converts unstable exchangeable phosphorus (Ex-P), ferric phosphate (Fe-P) and organic phosphorus (Or-P) into more stable occluded phosphate (O-P), reducing the possible release of phosphorus from sediments. Practical applications of ferric chloride to control the release of phosphorus from Dianchi Lake sediments were discussed.

Harvesting biomass of an oil-rich microalga Parachlorella kessleri TY02 by ferric chloride: Effects on harvesting efficiency, lipid production and municipal wastewater treatment.

Inorganic coagulants have been widely used to harvest microalgal biomass. A great deal of attention has been mainly focused on the response of harvesting efficiency, lipid production and feasibility of the reuse of medium to inorganic coagulants. The physiological state of harvested cells and feasibility of wastewater treatment remain unclear. In this context, the effect of ferric chloride as a conventional inorganic coagulant on the harvesting efficiency, physiological state and lipid content of an oil-rich microalga Parachlorella kessleri TY02 was evaluated. Moreover, the performance of harvested cells for municipal wastewater treatment was also evaluated. When the dosage of iron ions was 0.077 mg/mg dry biomass and the sedimentation time was 5 min, the microalga had good harvesting efficiency and cell viability. As the dosage of iron ions was up to 0.15 mg/mg dry biomass, cell viability notably decreased. Cells harvested by 0.077 and 0.15 mg/mg dry biomass of iron ions showed good wastewater treatment efficiency. It was also found that long sedimentation time (40 min) not only did not promote harvesting efficiency, but also reduced cell viability. Iron ions had no notable effect on lipid content of the microalga. Through comprehensive evaluation of harvesting efficiency, lipid production, physiological state and wastewater treatment efficiency, it indicated that 0.077 mg/mg dry biomass of iron ions could be used to harvest biomass of the microalga.

Effect of Water Chemistry on Antimony Removal by Chemical Coagulation: Implications of ζ-Potential and Size of Precipitates.

The process of coagulation and precipitation affect the fate and mobility of antimony (Sb) species in drinking water. Moreover, the solubility and physico-chemical properties of the precipitates may be affected by the media chemistry. Accordingly, the present study aimed to investigate the removal of Sb(III, V) species by ferric chloride coagulation under various water chemistry influences with a particular focus on the role of the properties of the precipitates. The results indicated that the amount of Sb(III) removed increased with increasing solution pH, showing the insignificant effects of the hydrodynamic diameter (HDD) and ζ-potential of the precipitates. However, no Sb(V) removal occurred at alkaline pH values, while a highly negative ζ-potential and the complete dissolution of precipitates were observed in the aqueous solution. The solution pH was also useful in determining the dominant coagulation mechanisms, such as co-precipitation and adsorption. The Fe solubility substantially affects the Sb removal at a certain pH range, while the HDD of the precipitates plays an insignificant role in Sb removal. The presence of divalent cations brings the ζ-potential of the precipitates close to point of zero charge (pzc), thus enhancing the Sb(V) removal at alkaline pH conditions. Pronounced adverse effects of humic acid were observed on Sb removal, ζ-potential and HDD of the precipitates. In general, this study may provide critical information to a wide group of researchers dealing with environmental protection from heavy metal pollution.

The Application of Ferric Chloride-Lignin Sulfonate as Shale Inhibitor in Water-Based Drilling Fluid.

A series of ferric chloride-lignin sulfonate (FCLS) was prepared from ferric chloride and lignin sulfonate to be used as shale inhibitor. The swelling rate of clay with FCLS-2 (w/w = 0.3%) decreased to 41.9%. Compared with control, FCLS-2 displayed high inhibitive ability against the hydrating and swelling processes of clay. Thus, the swelling degree of samples with FCLS-2 was much lower than that of the control, as well as the mud ball was more stable in FCLS-2 solution. Essentially, these excellent performances in inhibitor were assigned to the hydrogen bonding, electrostatic interaction and anchoring between FCLS-2 and other components. In addition, FCLS-2 has good compatibility with other common drilling fluid additives, and it can reduce the viscosity of systems, regardless of the room temperature or high temperature.

Enhanced Enzymatic Hydrolysis of Pennisetum alopecuroides by Dilute Acid, Alkaline and Ferric Chloride Pretreatments.

In this study, effects of different pretreatment methods on the enzymatic digestibility of Pennisetum alopecuroides, a ubiquitous wild grass in China, were investigated to evaluate its potential as a feedstock for biofuel production. The stalk samples were separately pretreated with H2SO4, NaOH and FeCl3 solutions of different concentrations at 120 °C for 30 min, after which enzymatic hydrolysis was conducted to measure the digestibility of pretreated samples. Results demonstrated that different pretreatments were effective at removing hemicellulose, among which ferric chloride pretreatment (FCP) gave the highest soluble sugar recovery (200.2 mg/g raw stalk) from the pretreatment stage. In comparison with FCP and dilute acid pretreatment (DAP), dilute alkaline pretreatment (DALP) induced much higher delignification and stronger morphological changes of the biomass, making it more accessible to hydrolysis enzymes. As a result, DALP using 1.2% NaOH showed the highest total soluble sugar yield through the whole process from pretreatment to enzymatic hydrolysis (508.5 mg/g raw stalk). The present work indicates that DALP and FCP have the potential to enhance the effective bioconversion of lignocellulosic biomass like P. alopecuroides, hence making this material a valuable and promising energy plant.

rLj-RGD3, a novel recombinant toxin protein from Lampetra japonica, prevents coronary thrombosis-induced acute myocardial infarction by inhibiting platelet functions in rats.

Recombinant Lampetra japonica RGD-peptide (rLj-RGD3), a soluble protein containing three RGD sequences, was acquired from the oral salivary glands of Lampetra japonica using recombinant DNA technology. The aim of this study was to investigate the protective effects of rLj-RGD3 against acute myocardial infarction (AMI) induced by coronary artery thrombosis, as well as the underlying mechanisms. A rat model of AMI caused by ferric chloride-induced thrombosis on the surface of the left anterior descending (LAD) coronary artery was successfully established. Rats were given various doses of rLj-RGD3 (12 µg/kg, 24 µg/kg and 48 µg/kg) via sublingual intravenous delivery 10 min before AMI. ST segment elevation was recorded by electrocardiogram (ECG) until the end of the model. Left ventricular Evans blue content and histopathological changes were examined. Blood samples were collected to determine 5-hydroxytryptamine (5-HT), ß-thromboglobulin (ß-TG), platelet factor 4 (PF4) and cAMP levels. The effects of rLj-RGD3 on platelet aggregation, adhesion and intracellular calcium concentrations were also measured. rLj-RGD3 significantly reduced ST segment elevation, prevented thrombus formation in the coronary artery and decreased Evans blue content in the left ventricular myocardium. Meanwhile, rLj-RGD3 exerted an inhibitory effect on adenosine diphosphate (ADP)-induced platelet aggregation and blocked platelet adhesion to collagen. Treatment with rLj-RGD3 prevented 5-HT, ß-TG and PF4 release and significantly elevated intracellular cAMP levels in a dose-dependent manner but decreased the level of cytosolic-free Ca2+, an aggregation-inducing molecule. These results show that rLj-RGD3 can effectively reduce coronary thrombosis in AMI rats by strongly inhibiting platelet function, indicating that the recombinant RGD toxin protein rLj-RGD3 may serve as a potent clinical therapeutic agent for AMI.

Elastin Stabilization Through Polyphenol and Ferric Chloride Combined Treatment for the Enhancement of Bioprosthetic Heart Valve Anticalcification.

The lifetime of bioprosthetic heart valves (BHVs) is limited by the mechanical damage and calcification. The major components of BHVs are collagen and elastin. Collagen could be well protected by glutaraldehyde (GLUT) crosslinking, while elastin is not stabilized and has a high risk of degradation, which could lead to the calcification of BHVs. We aimed to develop methods for stabilizing elastin and decreasing calcification. We investigated the combined tannic acid (TA) or epigallocatechin gallate (EGCG) with ferric chloride to stabilize elastin and prevent calcification. We found that the amount of TA/EGCG bound to elastin was in a time-dependent pattern and this reaction showed better efficiency in acidic condition and ethanol-water mixed solvents. Moreover, Fe3+ could compete with Ca2+ to bind to polyphenol, which could reduce the calcium deposition on BHVs. Cytotoxicity test showed that all extracts from different treatments had similar cell viabilities (85-100%). Through the combined treatments of polyphenol and ferric chloride, the pericardium had a better resistance to elastase degradation and more excellent anticalcification performance.

Comparison of different artificial neural network architectures in modeling of Chlorella sp. flocculation.

Biodiesel production from microalgae feedstock should be performed after growth and harvesting of the cells, and the most feasible method for harvesting and dewatering of microalgae is flocculation. Flocculation modeling can be used for evaluation and prediction of its performance under different affective parameters. However, the modeling of flocculation in microalgae is not simple and has not performed yet, under all experimental conditions, mostly due to different behaviors of microalgae cells during the process under different flocculation conditions. In the current study, the modeling of microalgae flocculation is studied with different neural network architectures. Microalgae species, Chlorella sp., was flocculated with ferric chloride under different conditions and then the experimental data modeled using artificial neural network. Neural network architectures of multilayer perceptron (MLP) and radial basis function architectures, failed to predict the targets successfully, though, modeling was effective with ensemble architecture of MLP networks. Comparison between the performances of the ensemble and each individual network explains the ability of the ensemble architecture in microalgae flocculation modeling.

Effect of Infant Formula on Streptococcus Mutans Biofilm Formation.

OBJECTIVE: This study investigated the effect that infant formula had on biofilm growth of Streptococcus mutans. Specifically, it compared biofilm growth in media containing lactose-based and sucrose-based formulas. It also analyzed biofilm formation with formulas of varying iron content. Biofilm growth was tested with the specific infant formula components sucrose, lactose, and ferric chloride. The study was designed to determine if these types of infant formulas and components affected S. mutans biofilm formation differently. STUDY DESIGN: A 24-hour culture of S. mutans was treated with various concentrations of infant formula diluted in bacteriological media. To test for biofilm formation, S. mutans was cultured with and without the infant formula and formula components. The biofilms were washed, fixed, and stained with crystal violet. The absorbance was measured to evaluate biofilm growth and total absorbance. RESULTS: Sucrose-based formulas provided significant increases in biofilm growth when compared to lactose-based formulas at two dilutions (1:5, 1:20). Similac Sensitive RS (sucrose-based) at most dilutions provided the most significant increase in biofilm growth when compared to the control. Sucrose tested as an individual component provided more of a significant increase on biofilm growth than lactose or iron when compared to the control. A low iron formula provided a significant increase in biofilm growth at one dilution (1:5) when compared to formula containing a normal iron content. There was no significant difference in biofilm growth when comparing high iron formula to normal iron formula or low iron formula. There was no significant difference when comparing Similac PM 60/40 (low iron formula) to Similac PM 60/40 with additional ferric chloride. CONCLUSION: The results of this study demonstrated that sucrose-based formula provided more of a significant increase in biofilm growth compared to lactose-based formula. Sucrose alone provided a significant increase of biofilm growth at more dilutions when compared to the control than lactose and iron. The amount of iron in formula had a significant effect on biofilm formation only when comparing low iron formula to normal iron formula at the highest concentration (1:5). There was no significant difference in biofilm growth when iron was added to the low iron formula. The information obtained expands current knowledge regarding the influence of infant formula on the primary dentition and reinforces the importance of oral hygiene habits once the first tooth erupts.

Comparison of short-term efficacy of iron sucrose with those of ferric chloride in hemodialysis patients: An open-label study.

BACKGROUND: It is intriguing and imperative that the comparison of the iron preparations in hemodialysis (HD) patients. This study aimed to observe the short-term efficacy of parenteral iron sucrose and ferric chloride in HD patients. MATERIALS AND METHODS: This was a consecutive 10-week single-blind study in Taiwan. An intravenous iron supplement of 100 mg/week was administered as an infusion in 100 ml of normal saline, until a total dose of 1000 mg was achieved. The primary outcome was evaluated by the changes in serum hematocrit (Hct) levels. The changes in serum Hct and iron indices were evaluated every 2 weeks for 10 weeks. The results were collected from 21 April to 4 July 2013. RESULTS: A total of 56 HD patients completed the study. Subjects were randomized into an iron sucrose group (26 patients) and a ferric chloride group (30 patients). Between the two treatment groups, there were no statistically significant differences in the change in serum Hct, ferritin, iron, or total iron binding capacity (P > 0.05). In the iron sucrose group, the increase in Hct levels was statistically significant at weeks 4, 8, and 10. In the ferric chloride group, the increase in Hct levels was statistically significant at week 8. No obvious major side effects were observed in both groups. CONCLUSION: In the study subjects, parenteral iron sucrose was as effective and safe as ferric chloride for treating anemia in HD patients.

Time-Dependent Thrombus Resolution After Tissue-Type Plasminogen Activator in Patients With Stroke and Mice.

BACKGROUND AND PURPOSE: We investigated the relationship between the degree of thrombus resolution and the time from stroke onset or thrombus formation to intravenous tissue-type plasminogen activator (tPA) treatment. METHODS: In patients with stroke, we measured thrombus volume on thin-section noncontrast brain computed tomographic scans taken at baseline and 1 hour after tPA administration. We determined the association between the time from symptom onset to tPA treatment and the degree of thrombus resolution. In a C57/BL6 mouse model of FeCl3-induced carotid artery thrombosis, we investigated the effect of tPA administered at different time intervals after thrombus formation, using Doppler-based blood flow measurement. RESULTS: Of 249 patients enrolled, 171 showed thrombus on baseline computed tomography. Thrombus was resolved by ≥50% in 43 patients (25.1%, good volume reduction) and by <50% in 94 patients (55.0%, moderate volume reduction) 1 hour after tPA treatment. In 34 patients (19.9%, nonvolume reduction; either no change or thrombus volume increased), overall thrombus volume increased. The probability of thrombus resolution decreased as the time interval from symptom onset to treatment increased. On multivariate analysis, good volume reduction was independently related with shorter time intervals from symptom onset to tPA treatment (odds ratio, 0.986 per minute saved; 95% confidence interval, 0.974-0.999). In the mouse model, as the interval between thrombus formation and tPA treatment increased, the initiation of recanalization was delayed (P=0.006) and the frequency of final recanalization decreased (P for trends=0.006). CONCLUSIONS: Early administration of tPA after stroke onset is associated with better thrombus resolution.

Commentary on "Arsenic mobility in the arsenic-contaminated Yangzonghai Lake in China" by Changliang Yang et al. [Ecotoxicology and Environmental Safety, 107(2014)321-327].

This commentary concerns some inaccuracy in recently published paper "Arsenic mobility in the arsenic-contaminated Yangzonghai Lake in China". Yang et al. raised an incorrect conclusion that after treatment with FeCl3 using the flocculation method, the sediments in the Yangzonghai Lake released As in the summer. The fundamental flaws of the paper which led to the incorrect conclusion were unreasonable sampling method for determining As concentration at various water depth and the wrong lake water volume of 6.04×10(8)m(3) (actually 4.8×10(8)m(3)) for calculating inventory of As in Yangzhonghai in August 2012. Then the authors attribute the As release in summer to the high concentration of HCO3(-) without any support of experimental data. Meanwhile, the authors designed a microbiological experiment to illustrate that increasing capacity of anaerobic microorganism could lead to As releasing from sediments. In our view point, this microbiological experiment was nonsense for evaluating the stability of As in sediments of Yangzonghai lake since the experimental conditions were greatly different from the natural conditions. Therefore, we conclude that the conclusions put forward by YANG are incorrect.

C-type lectin-like receptor-2 in platelets mediates ferric chloride-induced platelet activation and attenuates ferroptosis of endothelial cells.

BACKGROUND: An iron overload status induces ferroptosis, an iron-dependent nonapoptotic cell death, in various pathological conditions. We previously reported that hemin (heme), protoporphyrin-IX with ferric iron, activates platelets via C-type lectin-like receptor-2 (CLEC-2) and glycoprotein VI/FcRγ, but protoporphyrin-IX alone blocks CLEC-2-dependent platelet activation. Therefore, we hypothesized that free iron has the ability to activate platelets. OBJECTIVES: This study aimed to elucidate platelet activation mechanisms of iron (ferric chloride), including the identification of signaling pathways and receptors, and to examine whether platelets regulate ferroptosis. METHODS: Platelet aggregometry, platelet activation marker expression, and protein phosphorylation were examined in ferric chloride-stimulated human and murine platelets. Inhibitors of platelet activation signaling pathways and receptor-deleted platelets were utilized to identify the responsible signaling pathway and receptor. The effect of platelets on ferroptosis of endothelial cells was investigated in vitro. RESULTS: Ferric chloride induced platelet activation dependent on Src family kinase pathways in humans and mice. Ferric chloride-induced platelet aggregation was almost lost in CLEC-2-depleted murine platelets and wild-type platelets preincubated with recombinant CLEC-2 proteins. Furthermore, coculture of wild-type platelets, but not CLEC-2-deficient platelets, attenuated ferroptosis of endothelial cells in vitro. CONCLUSION: Ferric chloride activates platelets via CLEC-2 and Src family kinase pathways, and platelets have a protective role in the ferroptosis of endothelial cells dependent on CLEC-2.