Enhancement plaque control in preschool children by an intelligent brushing guide device.

This study aims to investigate the impact of a tooth-brushing guidance system on the enchancement of the dental plaque removal in preschool children. In this study, we selected a group of 124 healthy children in which their aged were between 3 and 5 years old following by treatment at the Pediatric Dentistry Center at Jinzhou Stomatological Hospital (JinZhou, Liaoning Province, China). We then followed up to check and identify the Turesky modification of the Quigley-Hein plaque index (TMQHPI). Study group was randomly assigned to an experimental group in which they received constantly guidance on intelligent tooth-brushing and a control group which was used by manual brushing techniques. The total numbers in each group were 62 participants that were gone under the clinical investigation for seven days. The plaque index of both groups were assessed by using a plaque display instrument and a periodontal probe for up day 28. It was shown that the experimental group had a lower average TMQHPI value (0.98 ± 0.15) in comparison with control group (1.41 ± 0.17), and this difference was statistically significant (p < 0.05). The experimental group had a significantly lower TMQHPI value (0.89 ± 0.13) on the tongue/palatal side of the anterior teeth area in comparison with control group (1.41 ± 0.17) (p < 0.05). We observed that experimental group showed significantly lower TMQHPI value (1.16 ± 0.12) on the tongue/palatal side of the posterior dental region in comparison with control group (1.70 ± 0.13) (p < 0.05). It was confirmed a significant difference in the average plaque clearance rate between the experimental and control groups (p < 0.05). Our study clearly indicates that a developed method of toothbrush guide effectively improved the removal rate of plaque compared with manual tooth-brush, specifically in hard-to-reach areas like the tongue and palate.

Comprehensive comparison of water quality risk and microbial ecology between new and old cast iron pipe distribution systems.

The effects of cast iron pipe corrosion on water quality risk and microbial ecology in drinking water distribution systems (DWDSs) were investigated. It was found that trihalomethane (THMs) concentration and antibiotic resistance genes (ARGs) increased sharply in the old DWDSs. Under the same residual chlorine concentration conditions, the adenosine triphosphate concentration in the effluent of old DWDSs (Eff-old) was significantly higher than that in the effluent of new DWDSs. Moreover, stronger bioflocculation ability and weaker hydrophobicity coexisted in the extracellular polymeric substances of Eff-old, meanwhile, iron particles could be well inserted into the structure of the biofilms to enhance the mechanical strength and stability of the biofilms, hence enhancing the formation of THMs. Old DWDSs significantly influenced the microbial community of bulk water and triggered stronger microbial antioxidant systems response, resulting in higher ARGs abundance. Corroded cast iron pipes induced a unique interaction system of biofilms, chlorine, and corrosion products. Therefore, as the age of cast iron pipes increases, the fluctuation of water quality and microbial ecology should be paid more attention to maintain the safety of tap water.

[Relationship between vitamin D and parathyroid hormone in Chinese elderly people].

OBJECTIVE: To explore the relationship between serum 25-hydroxyvitamin D(25(OH)D) and serum parathyroid hormone(PTH) level in Chinese people aged 50 years and above, and to probe the optimum threshold for vitamin D sufficiency preliminarily, and apply this threshold to predict the risk of metabolic syndrome(Mets) in this population. METHODS: A total of 750 serum samples were selected from the biological samples' bank of Chinese Chronic Diseases and Nutritional Survey(CCDNS, 2015-2017) by stratified sampling, basic information(including age, gender, season, etc. ) were collected from questionnaire and physical measurement of the subjects were conducted unified. Serum 25(OH)D concentration was determined by high performance liquid chromatography tandem mass spectrometer, and PTH and interleukin-6(IL-6) were detected by electrochemiluminescence method. Phosphorus, albumin(Alb), creatinine(Cr) in blood were detected by automatic biochemical analyzer. Factors affecting the concentration of 25(OH)D and PTH were found by multiple linear regression and adjusted by generalized additive model separately, threshold was predicted by locally weighted regression and smoothing scatterplot, abbreviated as LOESS, and the exact threshold of 25(OH)D was found when PTH reached the plateau by nonlinear least squares estimation and segmented regression. Relationship between 25(OH)D and Mets was analyzed by multivariate logistic regression using the different cut-off points in Chinese elderly people. RESULTS: Reference threshold for vitamin D deficiency in Chinese elderly people can be preliminarily discovered as serum total 25(OH)D was 19.62 ng/mL, and 28.44 ng/mL can be used as reference threshold for sufficient vitamin D. Sufficient 25(OH)D(≥28.44 ng/mL) could reduce the risk of Mets significantly(OR=0.617(0.439-0.869)) after adjusting for confounding factors such as sex, age, region, season, ect. A plateau in PTH was observed at a 25(OH)D concentration of 20.03-28.43 ng/mL for male whereas 13.12-26.33 ng/mL for female by gender stratification analysis, but no cut-off point was obtained statistically. CONCLUSION: Reference threshold for vitamin D sufficiency in Chinese elderly people was preliminarily observed in the range of 19.62-28.44 ng/mL when PTH was maximally inhibited, and the threshold may vary with gender. Applying the threshold we also found that more sufficient levels of vitamin D were protective against Mets in this population.

[Plasma selenium level and its influencing factors in Chinese child-bearing-aged women in 2015].

OBJECTIVE: To assess the plasma selenium(Se) level of child-bearing-aged women and discuss the influence factor for low-Se level. METHODS: Using the muti-stage stratified and population proportional cluster random sampling method, 1881 child-bearing-aged women aged 18 to 44 years were selected from China Adult Chronic Disease and Nutrition Surveillance(2015) Data. The basic information of the subjects was collected by unified electronic questionnaires and equipments were used for field survey, measurement and record. Plasma Se concentration was detected by inductively coupled plasma mass spectrometry. Plasma low-Se level were assessed using lower limit of plasma/serum Se established by the Mayo Clinic Laboratory and our laboratory, respectively. Influence factors of low-Se level were analyzed by the multivariate logistic regression model. RESULTS: The M(P25, P75) plasma Se concentration for Chinese child-bearing-aged women was 89.52(74.21, 105.03)µg/L. Nationality, location, urban-rural type and education level difference had influence on plasma Se level in this population(P<0.05). According to the lower limit of plasma/serum Se concentration established by the Mayo clinical laboratories(<70 µg/L) and our laboratories(<73.81 µg/L), the low-Se rate were 20.47% and 24.51%, respectively. There were significantly differences in low-Se rate among nationality, location, urban-rural type, education level and marital status(P<0.05). The multivariate logistic regression model showed that location and urban-rural type had significant effects on low-Se rate of child-bearing-aged women(P<0.05). CONCLUSION: The plasma low-Se rate of Chinese women of childbearing age is relatively high and higher prevalence low-Se was found in western and central regions and rural areas in China.

Development and identification of an elite wheat-Hordeum californicum T6HcS/6BL translocation line ND646 containing several desirable traits.

Hordeum californicum (H. californicum, 2n=2X=14, HcHc), one of the wild relatives of wheat (Triticum aestivum L.), harbors many desirable genes and is a potential genetic resource for wheat improvement. In this study, an elite line ND646 was selected from a BC4F5 population, which was developed using 60Co-γ irradiated wheat-H. californicum disomic addition line WJ28-1 (DA6Hc) as the donor parent and Ningchun 4 as the recurrent parent. ND646 was identified as a novel wheat-H. californicum 6HcS/6BL translocation line using genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), and H. californicum-specific expressed sequence tag (EST) markers. Further evaluation revealed that ND646 had excellent performance in several traits, such as a higher sedimentation value (SV), higher water absorption rate (WAR), and higher hardness index (HI). More importantly, it had more kernels per spike (KPS), a higher grain yields (GY), and good resistance to powdery mildew, leaf rust, and 2,4-D butylate (2,4-D). Its excellent phenotypic performance laid the foundation for further investigation of its genetic architecture and makes ND646 a useful germplasm resource for wheat breeding.

In vivo antiviral activity and disassembly mechanism of novel 1-phenyl-5-amine-4-pyrazole thioether derivatives against Tobacco mosaic virus.

A series of novel 1-phenyl-5-amine-4-pyrazole thioether derivatives containing a 1,3,4-oxadiazole moiety was designed and synthesised. In vivo antiviral bioassay results showed that most of the target compounds exhibited excellent inactivation activity against Tobacco mosaic virus (TMV). The EC50 values of the inactivation activities for T2, T7, T9, T24, T25 and T27 were 15.7, 15.7, 15.5, 11.9, 12.5 and 16.5 µg/mL, respectively, which were remarkably superior over that of the commercialised antiviral agent ningnanmycin (40.3 µg/mL). Morphological study using AFM and TEM of TMV treated with T24 showed that T24 could significantly shorten the polymerization length of TMV particles and formed a distinct break on the rod-shaped TMV. Investigations for virus infection efficiency on tobacco leaves demonstrated that infectivity of virion had been reduced obviously upon T24 treatment. Subsequently, a strong interaction between T24 and TMV-CP (Kd = 3.8 µM, score 6.11) was observed through MST experiments. Molecular docking study further revealed that target compounds interact with amino acid residue Glu50 in TMV CP, causing disassembly of virion, shorting the length of the virion and reducing the infectivity of virion, and resulting in high inactivating activity of target compounds. This study provides a new insight for discovery of antiviral compounds through a new action mechanism with a new binding site.

A novel SLC6A8 mutation associated with intellectual disabilities in a Chinese family exhibiting creatine transporter deficiency: case report.

BACKGROUND: X-linked creatine transporter deficiency (OMIM#300036,CRTR-D) is characterized by cerebral creatine deficiency, intellectual disabilities, severe speech impairment, seizures and behavioral problems. Mutations in the creatine transporter gene SLC6A8, a member of the solute-carrier family 6 mapped to Xq28, have been reported to cause the creatine transporter deficiency. CASE PRESENTATION: The proband presented at 5 yrs. 1 month of age with delays in intellectual and development, seizures and behavioral problems. A novel missense mutation, c.1181C > A (p.Thr394Lys), in the SLC6A8 gene (NM_005629.3) was detected via targeted exome sequencing, and then validated by Sanger sequencing. Multiple in silico variant effect analysis methods, including SIFT, PolyPhen2, PROVEAN, and Mutation Taster predicted that this variant was likely damaging or diseasing-causing. This hemizygous variation was also identified in the affected brother with the same clinical condition and inherited from the heterozygous carrier mother. The diagnosis was suggested by increased urinary creatine/creatinine (Cr:Crn) ratio and markedly reduced creatine content peak by brain proton magnetic resonance spectroscopy (MRS). The proband's mother became pregnant with a 3rd sibling, in whom the Sanger sequencing result of c.1181C > A was negative. CONCLUSION: The novel mutation c.1181C > A in the SLC6A8 gene reported in a Chinese family has expanded the mutation spectrum of CRTR-D. The combination of powerful new technologies such as targeted exome sequencing with thorough systematic clinical evaluation of patients will improve the diagnostic yield, and assist in genetic counselling and prenatal diagnosis for suspected genetic disorders.

Study on the mechanism of magnesium calcium alloys/mineralized collagen composites mediating macrophage polarization to promote bone repair.

Magnesium-based composites are a focal point in biomaterials research. However, the rapid degradation rate of magnesium alloys does not align with the healing time of bone tissue. Additionally, the host reaction caused by magnesium implantation hampers its full osteogenic potential. To maintain an appropriate microenvironment, it is important to enhance both corrosion resistance and osteogenic activity of the magnesium matrix. In this study, a composite scaffold composed of mineralized collagen and magnesium alloy was utilized to investigate the regulatory effect of mineralized collagen on mouse macrophages and evaluate its impact on mouse bone marrow mesenchymal stem cells in terms of osteogenesis, immune response, and macrophage-induced osteogenic differentiation. This experiment examined the biocompatibility of mouse bone marrow mesenchymal stem cells and macrophage-induced osteogenic differentiation in vitro, and examined the expression levels of relevant pathways proteins. Magnesium calcium alloys/mineralized collagen exhibited extensive spreading, facilitated by broad and abundant pseudopodia that firmly adhered them to the material surface and promoted growth and pseudopodia formation. The findings revealed that magnesium calcium alloy/mineralized collagen scaffold materials induced osteogenic differentiation mainly through M2 polarization of macrophages. This effect was mainly mediated by promoting the integrin α2ß1-FAK-ERK1/2 signaling pathways and inhibiting the RANK signaling pathways.

Study on the Dose-Response Relationship between Magnesium and Type 2 Diabetes of Childbearing Women in the China Adult Chronic Disease and Nutrition Surveillance 2015.

Background: Magnesium (Mg) is an essential element and participates in many metabolic pathways. Many studies have found a certain negative correlation between magnesium and blood glucose parameters, but the dose-response relationship between them is still a relatively narrow research field. We aim to explore the dose-response relationship between plasma and dietary Mg and type 2 diabetes (T2DM) among childbearing women in a nationally representative sample. And we will also initially explore the threshold of dietary and plasma magnesium in the prevention of T2DM and their consistency. Methods: A total of 2912 18-44 year-old childbearing women were recruited from the China Adult Chronic Disease and Nutrition Surveillance (2015). Multivariate logistic regression was used to explore the dose-response relationship between plasma and dietary Mg and glucose parameters. The threshold effect between Mg and T2DM was explored by a restricted cubic spline regression. Results: It was found that when plasma Mg was increased by 0.041 mmol/L, the risk of T2DM, impaired fasting glucose (IFG), and HbA1c-hyperglycemia was reduced by 18%, 19%, and 18%, respectively. The possible threshold value for plasma Mg to prevent the risk of T2DM was 0.87 mmol/L. Through the quality control of the sample dietary survey data, 2469 cases were finally included for dietary analysis. And the possible threshold value for dietary Mg to prevent the risk of T2DM was 408 mg/d. Taking the recommended dietary Mg intake of 330 mg/d as the reference group, when the Mg intake reached 408 mg/d, the risk of T2DM was significantly reduced. And the average plasma Mg level of the people whose dietary intake reached 408 mg/d was 0.87 mmol/L. Conclusions: These results indicate that dietary Mg and plasma Mg have good consistency on the threshold effect of glucose parameters in women of childbearing age.

Association and dose-response relationship of plasma magnesium with metabolic syndrome in Chinese adults older than 45 years.

Purpose: Magnesium (Mg) is an essential nutrient for the maintenance of vital physiological functions. Magnesium deficiency is associated with diseases such as obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome (MetS); however, conclusions have been inconsistent, and there is a particular lack of evidence regarding this association in Chinese population older than 45 years. This study aimed to assess the association between plasma magnesium and the risk of MetS and its components, the dose-response relationship, and the threshold effect relationship in a Chinese population involving older than 45 years. Methods: A total of 2,101 individuals were randomly selected from the China Nutrition and Health Surveillance (CNHS) (2015-2017) by considering monitoring points. We used the joint statement of the International Diabetes Federation (IDF) in 2009 to define participants with MetS. The plasma magnesium was tested by inductively coupled plasma mass spectrometry (ICP-MS). The logistic regression and restricted cubic spline (RCS) models were used to analyze the association and dose-response relationship between plasma Mg and MetS and its components. Results: Compared with the lowest quintile (Q1) for plasma Mg, the odds ratios (ORs) and 95% confidence intervals (95% CI) for MetS, impaired fasting glucose (IFG), hypertension, and triglyceride (TG) elevation at the highest quintile (Q5) were 0.419 (0.301, 0.583), 0.303 (0.221, 0.415), 0.446 (0.322, 0.618), and 0.526 (0.384, 0.720), respectively, with all p < 0.05. However, in the components of decreased high-density lipoprotein cholesterol (HDL-C) and central obesity, no trend toward lowering with higher plasma magnesium was observed (p = 0.717, p = 0.865). These associations were not altered by further adjustment for potential confounding variables, including age, gender, education, nationality, area, residence, body mass index (BMI), and heart rate. The RCS analysis showed that, when plasma magnesium was lower than 0.85 mmol/L, the curve was leveled off, and then, the curve showed a decreasing trend with the increase in plasma magnesium. Conclusion: Therefore, plasma Mg was negatively associated with MetS and its components (including IFG, hypertension, and elevated TG) in people older than 45 years. In addition, plasma Mg greater than or equal to 0.85 mmol/L, which is higher than the commonly used threshold of 0.75 mmol/L, may be protective against MetS and its components (including elevated FPG, elevated blood pressure, and elevated TG). More prospective studies, such as randomized controlled trials, are necessary to confirm the effective impact of Mg on MetS and its components. Plasma Mg levels in the MetS population older than 45 years require attention.

PCL-nHAC/Mg-Ca alloy composite and preliminary study of its osteogenesis property.

Owing to their excellent properties, magnesium alloys are widely used in bone tissue engineering. However, considerable work has been conducted to control the degradation rate and improve the cytocompatibility of magnesium alloys. In this study, low-cost production introduced a new bone repair composite (PCL-nHAC/Mg-Ca), which was composed of nano-hydroxylapatite-collagen (nHAC), polycaprolactone (PCL) and Mg-Ca alloy substrate treated by micro- arc oxidation (MAO). The experimental results showed that compared with the Mg-Ca alloy treated by MAO alone, the PCL-nHAC/Mg-Ca composite has a porous structure and a slower degradation rate. Cell experiments showed that the PCL-nHAC/Mg-Ca composite had good biocompatibility and significantly enhanced the proliferation of the MC3T3-E1 cells. The rabbit skull defect model further proved that the PCL-nHAC/Mg-Ca composite could regulate the degradation rate of the Mg-Ca alloy and promote the formation of bone tissue. Histological analyses showed that the PCL-nHAC/Mg-Ca composite had good stability in vivo and could better accelerate bone formation.

Role played by the physical structure of carbon anode materials in MFC biosensor for BOD measurement.

Microbial fuel cell (MFC) has been extensively studied as a biosensor for determining biochemical oxygen demand (BOD). The method for quantifying BOD by employing coulombic yield (Q) of a bio-electrochemical degradation process obtained from MFC biosensors is referred to as BODQ. The physical structures of anode materials greatly affect the sensitivity and accuracy of the biosensor. In this work, the effects of carbon cloth (CC) and carbon felt (CF) as anode substrate materials on the BODQ determination efficiencies were studied. The CF-MFC biosensor showed higher BODQ response than that of the CC-MFC within 25-400 mg L-1 BOD concentration range, and the test value was very close to the theoretical BOD. The difference is resulting from higher coulombic efficiency (CE) of CF-MFC (64.89-65.38 %) than CC-MFC (55.58-63.51 %). It should be noted that for water samples with low BOD concentrations the physical structures of anode materials play a leading role in CE. For synthetic wastewaters with 25 mg L-1 BOD, the CE of CF-MFC (65.38 %) was 17.63 % higher than that of CC-MFC (55.58 %). In contrast to the densely woven CC coated with thick biofilm, CF with loose carbon fiber and thin biofilm makes it good for organic diffusion and electron transportation, thus contributing to higher and more stable CE. These results indicate that the CF-MFC is more suitable for determining BODQ values over a wide concentration range. This work provides a useful strategy for selecting desirable MFC's anode material as the BOD biosensor. MFC biosensors with high-porosity biological anodes can obtain more accurate BOD test values.

Potential Fungicide Candidates: A Dual Action Mode Study of Novel Pyrazole-4-carboxamides against Gibberella zeae.

Pyrazole carboxamides are a class of traditional succinate dehydrogenase inhibitors (SDHIs) that have developed into a variety of commercialized fungicides. In the present work, a series of novel 1,5-disubstituted-1H-pyrazole-4-carboxamide derivatives were designed and synthesized based on the active backbone of 5-trifluoromethyl-1H-4-pyrazole carboxamide. Bioassay results indicated that some target compounds exhibited excellent in vitro antifungal activities against six phytopathogenic fungi. Notably, the EC50 values of Y47 against Gibberella zeae, Nigrospora oryzae, Thanatephorus cucumeris, and Verticillium dahliae were 5.2, 9.2, 12.8, and 17.6 mg/L, respectively. The in vivo protective and curative activities of Y47 at 100 mg/L against G. zeae on maize were 50.7 and 44.2%, respectively. Three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis revealed that the large steric hindrance and electronegative groups on the 5-position of the pyrazole ring were important for the activity. The IC50 value of Y47 against succinate dehydrogenase (SDH) was 7.7 mg/L, superior to fluopyram (24.7 mg/L), which was consistent with the docking results. Morphological studies with fluorescence microscopy (FM) and scanning electron microscopy (SEM) found that Y47 could affect the membrane integrity of mycelium by inducing endogenous reactive oxygen species (ROS) production and causing peroxidation of cellular lipids, which was further verified by the malondialdehyde (MDA) content. Antifungal mechanism analysis demonstrated that the target compound Y47 not only had significant SDH inhibition activity but could also affect the membrane integrity of mycelium, exhibiting obvious dual action modes. This research provides a novel approach to the development of traditional SDHIs and their derivatives.

Bisphenol A degradation by chlorine dioxide (ClO2) and S(IV)/ClO2 process: Mechanism, degradation pathways and toxicity assessment.

Recently, it has been reported that chlorine dioxide (ClO2) and (bi)sulfite/ClO2 showed excellent performance in micropollutant removal from water; however, the degradation mechanisms and application boundaries of the two system have not been identified. In this study, bisphenol A (BPA) was chosen as the target contaminant to give multiple comparisons of ClO2 and S(IV)/ClO2 process regarding the degradation performance of contaminant, generation of reactive species, transformation of products and toxicity variation. Both ClO2 and S(IV)/ClO2 can degrade BPA within 3 min. The BPA degradation mechanism was mainly based on direct oxidation in ClO2 process while it was attributed to radicals (especially SO4·-) generation in S(IV)/ClO2 process. Meanwhile, the effect of pH and coexisting substances (Cl-, Br-, HCO3- and HA) were evaluated. It was found that ClO2 preferred the neutral and alkaline condition and S(IV)/ClO2 preferred the acidic condition for BPA degradation. An unexpected speed-up of BPA degradation was observed in ClO2 process in the presence of Br-, HCO3- and HA. In addition, the intermediate products in BPA degradation were identified. Three exclusive products were found in ClO2 process, in which p-benzoquinone was considered to be the reason of the acute toxicity increase in ClO2 process.

The Magnesium Status and Suggested Reference Ranges of Plasma Magnesium, Calcium, and Calcium/Magnesium Ratio in Chinese Adults over 45 Years Old.

Magnesium (Mg) is an essential nutrient that participates in various enzymatic reactions and regulates important biological functions. The distribution and reference ranges in China have not been reported in populations more than 45 years old. This study aimed to assess the magnesium status and determine the reference values of plasma Mg, Ca, and Ca/Mg ratios for China's population more than 45 years old. A total of 2101 people were randomly selected from the China Nutrition and Health surveillance (CNHS) (2015-2017), considering the regional types and monitoring points. Then, 337 healthy individuals were further selected by a series of strict inclusion criteria to explore the reference range. The plasma magnesium and calcium were tested by inductively coupled plasma mass spectrometry (ICP-MS). The suggested reference values for plasma Mg, Ca, and Ca/Mg ratios were 0.75-1.14 mmol/L, 2.17-3.64 mmol/L, and 2.36-3.66, respectively. Taking 0.75 mmol/L as the lower cut-off limit, the prevalence of Mg deficiency was 6.66%, and the average level of plasma magnesium was 0.88 mmol/L for populations older than 45 years in China. In conclusion, this study provides the magnesium status and reference ranges for plasma Mg, Ca, and Ca/Mg ratio for Chinese people over 45 years old. The results of the recommended reference ranges in this study were very similar to our published results in women of reproductive age. Thus, the reference range of plasma magnesium in different populations in China was further improved.

Calcium sulfite oxidation activated by ferrous iron integrated with membrane filtration for removal of typical algal contaminants.

Oxidation treatment of algae-laden water may cause cells rupture and emission of intracellular organics, thus restricting its further popularization. As a moderate oxidant, calcium sulfite could be slowly released in the liquid phase, thus exhibiting a potential to maintain the cells integrity. To this end, calcium sulfite oxidation activated by ferrous iron was proposed integrated with ultrafiltration (UF) for removal of Microcystis aeruginosa, Chlorella vulgaris and Scenedesmus quadricauda. The organic pollutants were significantly eliminated, and the repulsion between algal cells was obviously weakened. Through fluorescent components extraction and molecular weights distribution analyses, the degradation of fluorescent substances and the generation of micromolecular organics were verified. Moreover, the algal cells were dramatically agglomerated and formed larger flocs under the premise of maintaining high cell integrity. The terminal normalized flux was ascended from 0.048-0.072 to 0.711-0.956, and the fouling resistances were extraordinarily decreased. Due to the distinctive spiny structure and minimal electrostatic repulsion, Scenedesmus quadricauda was easier to form flocs, and its fouling was more readily mitigated. The fouling mechanism was remarkably altered through postponing the formation of cake filtration. The membrane interface characteristics including microstructures and functional groups firmly proved the fouling control efficiency. The reactive oxygen species (i.e., SO4•- and 1O2) generated through the principal reactions and Fe-Ca composite flocs played dominant roles in alleviating membrane fouling. Overall, the proposed pretreatment exhibits a brilliant application potential for enhancing UF in algal removal.

Hydroxylamine enhanced the degradation of diclofenac in Cu(II)/peracetic acid system: Formation and contributions of CH3C(O)O•, CH3C(O)OO•, Cu(III) and •OH.

The slow reduction of Cu(II) into Cu(I) through peracetic acid (PAA) heavily limited the widespread application of Cu(II)/PAA system. Herein, hydroxylamine (HA) was proposed to boost the oxidative capacity of Cu(II)/PAA system by facilitating the redox cycle of Cu(I)/Cu(II). HA/Cu(II)/PAA system was quite rapid in the removal of diclofenac within a broad pH range of 4.5-9.5, with a 10-fold increase in the removal rate of diclofenac compared with the Cu(II)/PAA system at an optimal initial pH of 8.5. Results of UV-Vis spectra, electron paramagnetic resonance, and alcohol quenching experiments demonstrated that CH3C(O)O•, CH3C(O)OO•, Cu(III), and •OH were involved in HA/Cu(II)/PAA system, while CH3C(O)OO• was verified as the predominant reactive species of diclofenac elimination. Different from previously reported Cu-catalyzed PAA processes, CH3C(O)OO• mainly generated from the reaction of PAA with Cu(III) rather than CH3C(O)O• and •OH. Four possible elimination pathways for diclofenac were proposed, and the acute toxicity of treated diclofenac solution with HA/Cu(II)/PAA system significantly decreased. Moreover, HA/Cu(II)/PAA system possessed a strong anti-interference ability towards the commonly existent water matrix. This research proposed an effective strategy to boost the oxidative capacity of Cu(II)/PAA system and might promote its potential application, especially in copper-contained wastewater.

Enhanced Heterogeneous Fenton Degradation of Organic Pollutants by CRC/Fe3O4 Catalyst at Neutral pH.

Fe3O4-based heterogeneous Fenton catalysts have been widely employed for degrading organic pollutants, however it is challenging to use them in highly efficient and recyclable application in wastewater treatment. In this work, carboxylate-rich carbon (CRC)-modified Fe3O4 magnetic particles are prepared by the sol-gel self-combustion method, where CRC is obtained from the carbonization of sodium gluconate. The CRC/Fe3O4 catalyst exhibits high heterogeneous Fenton degradation performance. The complete 10 mg L-1 methylene blue (MB) removal is achieved in 180 min under conditions of 10 mM H2O2 and 1.00 g of L-1 CRC/Fe3O4 at neutral pH. After five cycles, the structure and morphology of CRC/Fe3O4 composites remained unchanged and the catalytic activity also remained unaltered. Moreover, phenol, benzoic acid (BA), sulfamethazine (SMT), and tetracycline (TC) were also degraded in the heterogeneous Fenton reaction using CRC/Fe3O4 as a catalyst. The strong coordinating ability of -COOH/ -COO- functionalities of CRC formed strong bonds with Fe(II/III) ions on the surfaces of Fe3O4 particles, which was conducive to adsorption of organic matter on the surface of the catalyst and promoted the occurrence of heterogeneous Fenton reactions. It was found that CRC/Fe3O4 had higher removal rates for the adsorptive exclusions of pollutants, such as TC and MB, whereas there were lower removal rates for phenol, BA, and SMT. This work brings potential insights for development of a novel adsorption-enhanced heterogeneous Fenton reaction for wastewater treatment.

Corrigendum: Enhanced Heterogeneous Fenton Degradation of Organic Pollutants by CRC/Fe3O4 Catalyst at Neutral pH.

[This corrects the article DOI: 10.3389/fchem.2022.892424.].

In vitro evaluation of freeze-drying chitosan-mineralized collagen/Mg-Ca alloy composites for osteogenesis.

Magnesium (Mg) alloy with good mechanical properties and biodegradability is considered as one of the ideal bone repair materials. However, the rapid corrosion of Mg-based metals can pose harm to the function of an implant in clinical applications. In this study, micro-arc oxidation coating was prepared on the surface of the Mg-Ca matrix, then the chitosan and mineralized collagen (nano-hydroxyapatite/collagen; nHAC) were immobilized on the surface of the MAO/Mg-Ca matrix to construct the CS-nHAC/Mg-Ca composites of different component proportions (the ratio of CS to nHAC is 2:1, 1:1, and 1:2, respectively). The corrosion resistance, osteogenic activity, and angiogenic ability were extensively investigated. The results indicated that the CS-nHAC reinforcement materials can improve the corrosion resistance of the Mg matrix significantly and promote the proliferation and adhesion of mouse embryo osteoblast precursor cells (MC3T3-E1) and human umbilical vein endothelial cells (HUVECs). In addition, the CS-nHAC/Mg-Ca composites can not only promote the alkaline phosphatase (ALP) activity and extracellular matrix mineralization of MC3T3-E1 cells but also enhance the migration motility and vascular endothelial growth factor (VEGF) expression of HUVECs. Meanwhile, the 2CS-1nHAC/Mg-Ca composite exhibited the optimum function characteristics compared with other samples. Therefore, considering the improvement of corrosion resistance and biocompatibility, the CS-nHAC/Mg-Ca composites are expected to be a promising orthopedic implant.