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Exploring low-cost and high-performance phosphorus (P) adsorbents is key to controlling P contamination in water. This study evaluated the P adsorption performance of three types of cement: Ordinary Portland cement (OPC), Portland slag cement (PSC), and Portland pozzolana cement (PPC). Furthermore, SEM-EDS, XRD, XPS, and FTIR were employed to reveal the adsorption mechanism. The results showed that the pseudo-second-order model exhibited higher regression coefficients than the pseudo-first-order model, indicating that chemisorption dominated the adsorption process. The Langmuir equation fitted the P adsorption data well, with maximum P adsorption capacities of 245.8, 226.1, and 210.0 mg g -1 for OPC, PSC, and PPC at 25 °C, respectively. P adsorption capacities decreased gradually with increasing initial pH and reached their maximum values at pH 3. The anions of F - , CO 3 2- , and SO 4 2- negatively affected P adsorption due to the competitive adsorption with Ca 2+ . The results of XPS, XRD, and FTIR confirmed that Ca-P precipitates ( i.e. , hydroxyapatite) were the main removal mechanism. A real domestic sewage experiment showed that 0.6 g L -1 OPC effectively reduced the P concentration from 2.4 to below 0.2 mg L -1 , with a dosage cost of 0.034 $ per ton. This study indicated that cement, as a low-cost and efficient P adsorbent, has great potential for application in removing P from acidic and neutral wastewater., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Utilizing alkaline solid wastes, such as steel slag, as substrates in tidal flow constructed wetlands (TFCWs) can effectively neutralize the acidity generated by nitrification. However, the impacts of steel slag on microbial communities and the potential risk of heavy metal release remain poorly understood. To address these knowledge gaps, this study compared the performance and microbial community structure of TFCWs filled with a mixture of steel slag and zeolite (TFCW-S) to those filled with zeolite alone (TFCW-Z). TFCW-S exhibited a much higher NH 4 + -N removal efficiency (98.35 %) than TFCW-Z (55.26 %). Additionally, TFCW-S also achieved better TN and TP removal. The steel slag addition helped maintain the TFCW-S effluent pH at around 7.5, while the TFCW-Z effluent pH varied from 3.74 to 6.25. The nitrification and denitrification intensities in TFCW-S substrates were significantly higher than those in TFCW-Z, consistent with the observed removal performance. Moreover, steel slag did not cause excessive heavy metal release, as the effluent concentrations were below the standard limits. Microbial community analysis revealed that ammonia-oxidizing bacteria, ammonia-oxidizing archaea, and complete ammonia-oxidizing bacteria coexisted in both TFCWs, albeit with different compositions. Furthermore, the enrichment of heterotrophic nitrification-aerobic denitrification bacteria in TFCW-S likely contributed to the high NH 4 + -N removal. In summary, these findings demonstrate that the combined use of steel slag and zeolite in TFCWs creates favorable pH conditions for ammonia-oxidizing microorganisms, leading to efficient ammonia removal in an environmentally friendly manner., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Long-term in situ measurements of the temperature of hydrothermal fluids have great significance in the research of seafloor hydrothermal activities. Herein, we developed a self-powered battery-free temperature logger for measuring and recording the temperature of hydrothermal fluids. A gravity heat pipe made of titanium alloy was employed as the heat-conducting element of the temperature logger to capture heat from a hydrothermal vent and transfer it to the thermoelectric unit. The thermoelectric generator used herein converted the temperature difference into electrical energy to power the circuit of the temperature logger. Numerical analyses and experiments were performed to investigate the performance of the heat pipe and temperature logger. Results show that the temperature logger can realize self-powered starting at a temperature of >76 °C during a tank test. This paper presents a discussion on a new instrument for temperature measurements of deep-sea hydrothermal fluids., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

Macadamia oil cake (MOC) is a type of macadamia nut by-product, that is extremely rich in amino acids and has beneficial health effects. It lowers blood lipid levels and regulates the intestinal microbiota. MOC effectively attenuated total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels in model rats. Depending on the morphology of the colon, MOC can effectively attenuate damage to the tissue structure. The 16S rDNA gene of the rat intestinal microbiota was sequenced using Illumina PE250 high-throughput sequencing technology, and the changes in the intestinal microbiota in each group are discussed. Supplementing MOC at different doses significantly increased the microbiota of Dorea , Erysipelotrichaceae , Stercoris , etc. in the intestinal tracts of rats fed a high-fat diet. Therefore, MOC can be included in lipid healthy dietary patterns to lower lipid characteristics and restructure the intestinal microbiota. Future clinical trials are required to determine the therapeutic effects and mechanisms of hypolipidemia., Competing Interests: There is no conflict of interest., (© 2023 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Calcium oxalate (CaOx) crystals in plants act as a sink for excess Ca and play an essential role in detoxifying heavy metals (HMs). However, the mechanism and related influencing factors remain unclear. Amaranth (Amaranthus tricolor L.) is a common edible vegetable rich in CaOx and a potential Cd hyperaccumulation species. In this study, the hydroponic experiment was carried out to investigate the effect of exogenous Ca concentrations on Cd uptake by amaranth. The results showed that either insufficient or excess Ca supply inhibited amaranth growth, while the Cd bioconcentration factor (BCF) increased with Ca concentration. Meanwhile, the sequence extraction results demonstrated that Cd mainly accumulated as pectate and protein-bound species (NaCl extracted) in the root and stem, compared to pectate, protein, and phosphate-bound (acetic acid extractable) species in the leaf. Correlation analysis showed that the concentration of exogenous Ca was positively correlated with amaranth-produced CaOx crystals but negatively correlated with insoluble oxalate-bound Cd in the leaf. However, since the accumulated insoluble oxalate-bound Cd was relatively low, Cd detoxification via the CaOx pathway in amaranth is limited., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The formation of As(V) substituted hydroxylapatite (HAP) has a vital influence on the fate of As(V) in the environment. However, despite growing evidence showing that HAP crystallizes in vivo and in vitro with amorphous calcium phosphate (ACP) as a precursor, a knowledge gap exists concerning the transformation from arsenate-bearing ACP (AsACP) to arsenate-bearing HAP (AsHAP). Here we synthesized AsACP nano-particles with varied As contents and investigated the arsenic incorporation during their phase evolution. The phase evolution results showed that the transformation process of AsACP to AsHAP could be divided into three Stages. A higher As(V) loading significantly delayed the transformation of AsACP, increased the distortion degree, and decreased the crystallinity of AsHAP. NMR result showed that the PO 4 3- tetrahedral is geometrically preserved when PO 4 3- is substituted by AsO 4 3- . From AsACP to AsHAP, the As-substitution led to the transformation inhibition and As(V) immobilization., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Runliang Zhu reports financial support was provided by Fundamental and Applied Fundamental Research Major Program of Guangdong Province. Shijun Wu reports financial support was provided by Guangdong Basic and Applied Basic Research Foundation. Shijun Wu reports financial support was provided by National Natural Science Foundation of China. Tim White reports financial support was provided by Monetary Academic Resources for Research Grant. Yao Yan reports financial support was provided by China Scholarship Council., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The transition areas of riverine, estuarine, and marine environments are particularly valuable for the research of microbial ecology, biogeochemical processes, and other physical-chemical studies. Although a large number of microbial-related studies have been conducted within such systems, the vast majority of sampling have been conducted over a large span of time and distance, which may lead to separate batches of samples receiving interference from different factors, thus increasing or decreasing the variability between samples to some extent. In this study, a new in situ filtration system was used to collect membrane samples from six different sampling sites along the Sanya River, from upstream freshwater to the sea, over a nine-hour period. We used high-throughput sequencing of 16S and 18S rRNA genes to analyze the diversity and composition of prokaryotic and eukaryotic communities. The results showed that the structures of these communities varied according to the different sampling sites. The α-diversity of the prokaryotic and eukaryotic communities both decreased gradually along the downstream course. The structural composition of prokaryotic and eukaryotic communities changed continuously with the direction of river flow; for example, the relative abundances of Rhodobacteraceae and Flavobacteriaceae increased with distance downstream, while Sporichthyaceae and Comamonadaceae decreased. Some prokaryotic taxa, such as Phycisphaeraceae and Chromobacteriaceae , were present nearly exclusively in pure freshwater environments, while some additional prokaryotic taxa, including the SAR86 clade , Clade I , AEGEAN-169 marine group , and Actinomarinaceae , were barely present in pure freshwater environments. The eukaryotic communities were mainly composed of the Chlorellales X , Chlamydomonadales X , Sphaeropleales X , Trebouxiophyceae XX , Annelida XX , and Heteroconchia . The prokaryotic and eukaryotic communities were split into abundant, common, and rare communities for NCM analysis, respectively, and the results showed that assembly of the rare community assembly was more impacted by stochastic processes and less restricted by species dispersal than that of abundant and common microbial communities for both prokaryotes and eukaryotes. Overall, this study provides a valuable reference and new perspectives on microbial ecology during the transition from freshwater rivers to estuaries and the sea.

The organic modification of three-dimensional porous diatom frustules (biosilica) and their fossils (diatomite) is promising in heavy metal adsorption. However, the preparation of such materials involves complex processes, high costs, and environmental hazards. In this study, organic-biosilica composites based on in situ self-modification of diatoms were prepared by freeze-drying pretreatment. Freeze-drying resulted in the release of the intercellular organic components of diatoms, followed by loading on the surface of their diatom frustules. The bio-adsorbent exhibits outstanding Cd 2+ adsorption capacity (up to 220.3 mg/g). The adsorption isotherms fitted the Langmuir model and the maximum adsorption capacity was 4 times greater than that of diatom biosilica (54.1 mg/g). The adsorption kinetics of Cd 2+ was adequately described by a pseudo-second-order model and reached equilibrium within 30 min. By combining focused ion beam thinning with transmission electron microscopy-energy dispersive X-ray spectroscopy, the internal structure of the composite and the Cd 2+ distribution were investigated. The results showed that the organic matter of the composite adsorbed approximately 10 times more Cd 2+ than inorganic biosilica. The adsorption mechanism was dominated by complexation between the abundant organic functional groups (amide, carboxyl, and amino groups) on the surfaces of composite and Cd 2+ . The bio-adsorbent was demonstrated to have wide applicability in the presence of competitive cations (Na + , K + , Ca 2+ , and Mg 2+ ) and under a wide range of pH (3-10) conditions. Thus, the self-modification of diatoms offers a promising organic-inorganic composite for heavy metal remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Microbial-induced carbonate precipitation (MICP) is a promising technology to immobilize/remediate heavy metals (HMs) like cadmium (Cd). However, the long-term stability of MICP-immobilized HMs is unclear, especially in farmland where chemical fertilization is necessary. Therefore, we performed MICP treatment on soils contaminated with various Cd compounds (CdCO 3 , CdS, and CdCl 2 ) and added diammonium phosphate (DAP) to explore the impact of phosphate on the MICP-immobilized Cd. The results showed that MICP treatment was practical to immobilize the exchangeable Cd but to mobilize the carbonate and Fe/Mn oxide-bound Cd. After applying DAP, soil pH declined due to ammonium nitrification. At high P/Ca molar ratios (1/2 and 1), partial previously immobilized Cd was released due to the carbonate dissolution. Contrarily, exchangeable Cd transformed to less mobilizable Fe/Mn oxide-bound at low P/Ca molar ratios (1/4 and 1/8). Meanwhile, other treatments were also helpful in avoiding the release of immobilized Cd, such as applying non-ammonium phosphate and adding lime material after soil acidification. Our investigation suggested that the long-term stability of HMs in remediated sites should be carefully evaluated, especially in agricultural areas with phosphate and nitrogen fertilizer input., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Runliang Zhu reports financial support was provided by Fundamental and Applied Fundamental Research Major Program of Guangdong Province. Shijun Wu reports financial support was provided by National Natural Science Foundation of China. Shijun Wu reports financial support was provided by Guangdong Basic and Applied Basic Research Foundation. Shijun Wu reports financial support was provided by Science and Technology Planning Project of Guangdong Province., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Carbonate-bound speciation is a critical sink of potentially toxic elements (PTEs) like cadmium (Cd) in soil and sediment. In a phosphate-rich environment, carbonate minerals could be replaced by phosphate minerals such as dicalcium phosphate dihydrate (DCPD, also known as brushite), octacalcium phosphate (OCP), and hydroxylapatite (HAP). Currently, it is unclear the migration and fate of PTEs during the replacement of PTEs-bearing carbonates by HAP and related intermediate minerals. Therefore, we synthesized Cd-bearing calcite by the coprecipitation method and converted it to DCPD, OCP, and HAP to investigate the redistribution and fate of Cd. The results showed that Cd incorporation in calcite significantly inhibited their replacement by DCPD and OCP, respectively. 1.26% of Cd in calcite was released into the solution when DCPD replaced calcite, and subsequently, most of the released Cd was recaptured by OCP. Significantly, the released Cd was below 0.05‰ when all the solid converted to HAP. These results suggested that with the application of phosphate fertilizer in alkaline soil, the secondary calcium phosphate minerals could control the environmental behavior of Cd., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Shijun Wu reports financial support was provided by National Natural Science Foundation of China. Shijun Wu reports financial support was provided by Guangdong Basic and Applied Basic Research Foundation. Runliang Zhu reports was provided by Fundamental and Applied Fundamental Research Major Program of Guangdong Province. Shijun Wu, Yongqiang Yang, Fanrong Chen, Runliang Zhu reports financial support was provided by Science and Technology Planning Project of Guangdong Province., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The ammonia removal performance of tidal flow constructed wetlands (TFCWs) requires to be improved under high hydraulic loading rates (HLRs). The pH decrease caused by nitrification may adversely affect the NH 4 + -N removal and ammonia-oxidizing microorganisms (AOMs) of TFCWs. Herein, TFCWs with zeolite (TFCW_Z) and a mixture of zeolite and steel slag (TFCW_S) were built to investigate the influence of steel slag on NH 4 + -N removal and AOMs. Both TFCWs were operated under short flooding/drying (F/D) cycles and high HLRs (3.13 and 4.69 m 3 /(m 2 d)). The results revealed that a neutral effluent pH (6.98-7.82) was achieved in TFCW_S owing to the CaO dissolution of steel slag. The NH 4 + -N removal efficiencies in TFCW_S (91.2 ± 5.1%) were much higher than those in TFCW_Z (73.2 ± 7.1%). Total nitrogen (TN) removal was poor in both TFCWs mainly due to the low influent COD/TN. Phosphorus removal in TFCW_S was unsatisfactory because of the short hydraulic retention time. The addition of steel slag stimulated the flourishing AOMs, including Nitrosomonas (ammonia-oxidizing bacteria, AOB), Candidatus_Nitrocosmicus (ammonia-oxidizing archaea, AOA), and comammox Nitrospira, which may be responsible for the better ammonia removal performance in TFCW_S. PICRUSt2 showed that steel slag also enriched the relative abundance of functional genes involved in nitrification (amoCAB, hao, and nxrAB) but inhibited genes related to denitrification (nirK, norB, and nosZ). Quantitative polymerase chain reaction (qPCR) revealed that complete AOB (CAOB) and AOB contributed more to the amoA genes in TFCW_S and TFCW_Z, respectively. Therefore, this study revealed that the dominant AOMs could be significantly changed in zeolite-based TFCW by adding steel slag to regulate the pH in situ, resulting in a more efficient NH 4 + -N removal performance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Carbonate-bound uranium (U) is critical in controlling the migration of U in circumneutral to alkaline conditions. The potential release risk of carbonate-bound U should be concerned due to the contribution of mineral replacement. Herein, we explored the fate of U during the conversion process from microbial-induced calcite to hydroxylapatite (HAP) and investigated the phase and morphology evolution of minerals and the immobilization efficiency, distribution, and stability of U. The results showed that most calcite could convert to HAP during the conversion process. The aqueous residual U was below 1.0 mg/L after U-HAP formation, and the U removal efficiencies were enhanced by 20.0-74.4% compared to the calcite precipitation process. XRD and TEM results showed that the products were a mixture of HAP and uramphite. The elemental mapping results showed that most U concentrated on uramphite while a handful of U distributed homogeneously in calcite and HAP matrixes. The stability test verified that U-bearing HAP decreased the U solubility by 98-100% relative to calcite due to the uramphite formation and U incorporation into HAP. Our findings demonstrated that the combinations of microbial-induced calcite precipitation and calcite-HAP conversion could facilitate the U immobilization in treating radioactive wastewater and soil., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Novel Pt/Bi 3.4 Gd 0.6 Ti 3 O 12 heterojunction was synthesized by a decoration of Pt nanoparticles (PtNPs) on the surface of piezoelectric Bi 3.4 Gd 0.6 Ti 3 O 12 (BGTO) through an impregnation process. The photocatalytic, piezo-catalytic, and piezo-photocatalytic activities of the Pt/BGTO heterojunction for methyl orange (MO) degradation were investigated under ultrasonic excitation and whole spectrum light irradiation. The internal piezoelectric field of BGTO and a plasmonic effect have been proven important for the photocatalytic activity of the heterojunctions. Pt/BGTO exhibited an optimum photocatalytic degradation performance of 92% for MO in 70 min under irradiation of whole light spectrum and ultrasonic coexcitation, and this value was about 1.41 times higher than the degradation rate under whole spectrum light irradiation alone. The PtNPs in Pt/BGTO heterojunction can absorb the incident light intensively, and induce the collective oscillation of surface electrons due to the surface plasmon resonance (SPR) effect, thus generating "hot" electron-hole pairs. The internal piezoelectric field produced in BGTO by ultrasonic can promote the separation of SPR-induced "hot" charge carriers and facilitate the production of highly reactive oxidation radicals, thus enhancing Pt/BGTO heterojunction's photocatalytic activity for oxidizing organic dyes.

Gram-negative bacteria usually use acyl-homoserine lactones (AHLs)-mediated LuxI/LuxR-type quorum sensing (QS) systems for cell-cell cooperation and/or bacteria-environment communication. LuxI and LuxR are AHLs synthase and receptor, respectively. These two parts could form a positive regulatory feedback loop, controlling various types of group behaviors. However, the autoregulation mechanisms between them are fragmented and could be highly differentiated in different bacteria. Here, we clarified the autoregulation mechanism between LuxI and LuxR in Pseudoalteromonas sp. R3. YasI (LuxI in strain R3) synthesizes two types of AHLs, C8-HSL and 3-OH-C8-HSL. It is worth noting that YasR (LuxR in strain R3) only responds to C8-HSL rather than 3-OH-C8-HSL. YasR-C8HSL can activate the yasI transcription by recognizing "lux box" at yasI upstream. Interestingly, YasR can directly promote the yasR expression with AHL-independent manner, but AHL absence caused by the yasI-deficiency led to the significant decrease in the yasR expression. Further study demonstrated that the yasI-deficiency can result in the decrease in the yasR mRNA stability. Notably, both yasI-deficiency and yasR-deficiency led to the significant decrease in the expression of hfq encoding RNA chaperone. Therefore, it was speculated that not only YasR itself can directly regulate the yasR transcription, but YasR-C8HSL complex indirectly affects the yasR mRNA stability by regulating Hfq., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Pseudoalteromonas spp. are Gram-negative bacteria which are ubiquitous in marine environments. Our previous work found that there is a classic LuxI/LuxR-type quorum sensing (QS) system which was named YasI/YasR in Pseudoalteromonas sp. R3, but the factors that control QS in strain R3 are unclear yet. Here, we found that the deficiency of hfq encoding RNA chaperon Hfq down-regulated the transcription levels of yasI encoding acyl-homoserine lactones (AHLs) synthase and yasR encoding AHLs receptor in strain R3. The assay based on fusion reporter of yasI-lacZ showed that Hfq regulates the expression of yasR at both transcriptional and translational levels. In addition, Hfq affects the expression of yasI via yasR. Further analysis indicated that the 5'UTR region of yasR is necessary for Hfq to control QS. In addition, the deletion of hfq increases the unstability of the target yasR mRNA. Based on transcriptome sequencing and bioinformatic analysis together with molecular experiments, Hfq-dependent sRNA00002 was identified to be involved in positively regulating QS in Pseudoalternas sp. R3. It was found that sRNA00002 deficiency causes the decrease in expression of yasI and yasR, and thus abolishes the production of AHLs in strain R3. It was concluded that Hfq-dependent sRNA00002 regulates yasR expression by base-pairing with target yasR mRNA at 5'UTR region and altering the stability of yasR mRNA. Our work paves the way for understanding the regulation mechanism of Hfq-dependent sRNAs on QS in Pseudoalteromonas., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: This study aimed to investigate the association of elementary school students' manipulative skill competency, cardiorespiratory fitness, and cognitive function with psychological wellbeing (PWB), as well as whether the association had gender differences., Methods: Participants were 291 fourth-grade students (166 boys vs. 125 girls; mean age = 9.770 years old; SD = 0.584) at two elementary schools from the province of Henan in China. The students' soccer skills in manipulative skill competency were assessed using the PE Metric Assessment Rubric, cardiorespiratory fitness was assessed by means of the PACER 15 m test, and cognitive function and PWB were assessed using the d2 test of attention and Warwick-Edinburgh Mental Wellbeing Scale, respectively. Data were analyzed with descriptive statistics and multiple linear regression models., Results: The result of linear regression models showed that soccer skills, cardiorespiratory fitness, and cognitive function were collectively associated with PWB for the total sample ( F (5, 285) = 3.097, p < 0.01), boys ( F (5, 160) = 1.355, p < 0.01), and girls ( F (5, 119) = 2.132, p < 0.01). Furthermore, the standardized regression coefficients ( β ) indicated that cardiorespiratory fitness was the only significant contributor to PWB for the total sample ( β = 0.119, t = 2.021, p < 0.05), but not for boys and girls. Soccer skills and cognitive function were not individual significant contributors to PWB for the total sample, boys, and girls., Conclusions: Cardiorespiratory fitness was significantly associated with PWB, and there were no gender differences in the relationship of manipulative skill competency, cardiorespiratory fitness, and cognitive function with PWB in elementary school students. This study provides empirical evidence that improving cardiorespiratory fitness is an important intervention strategy to promote elementary school students' PWB.

Dissolution-precipitation processes on the surface of brushite (dicalcium phosphate dihydrate, DCPD) control the migration and transformation of potentially harmful elements (PHEs). The incorporation of impurities could affect the properties of DCPD and its interactions with PHEs. In this study, we synthesized Fe 3+ -bearing DCPD via coprecipitation and investigated the influence of Fe 3+ incorporation on the crystal structure, hydrolysis process, and Cd removal performance. Fe-bearing DCPD had lattice expansion due to the coupled substitution of Fe 3+ and NH 4 + for Ca 2+ . Therefore, the Cd removal performance of Fe-DCPD was enhanced, with a maximum Cd uptake capacity of 431.6 mg/g, which is 1.77 times that of Fe-free DCPD (244.4 mg/g). Furthermore, Fe-DCPD also exhibited a faster hydrolysis rate, which was up to 2.67 times that of Fe-free DCPD and accelerated Cd's transfer to the stable host mineral, hydroxylapatite. Cd was first caught by the DCPD surface in a weakly crystalline form and then incorporated into the hydroxylapatite structure during crystallization. Based on the X-ray photoelectron spectroscopy and thermogravimetric analysis results, we concluded that the decrease in interstitial water due to Fe incorporation was responsible for accelerating hydrolysis and enhancing Cd immobilization. In all, the incorporation of Fe 3+ into DCPD could promote its transformation and improve its Cd uptake capacity. Our results suggest that Fe-DCPD could be a promising candidate for environmental remediation., Competing Interests: Declaration of competing interest None., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Coprecipitation with calcium carbonate (CaCO 3 ) could decrease the bioavailability of arsenic (As). However, in a phosphate-rich environment, some CaCO 3 will be converted to hydroxylapatite (HAP). Currently, the behavior of carbonate-bound As during conversion is unclear. Therefore, we prepared bio-induced CaCO 3 in an As solution and converted it to HAP. The results showed that a high concentration of arsenate promoted vaterite precipitation and the conversion of CaCO 3 to HAP. The dissolution data verified the low solubility of As in HAP, though its As-bearing CaCO 3 precursor released up to 88.19% As during the conversion. Furthermore, HPLC-ICP-MS data showed partial oxidation of arsenite to arsenate, suggesting that CaCO 3 and HAP's structure favored the incorporation of arsenate. Our results demonstrated that the stability of heavy metal-bearing CaCO 3 should be considered, and the role of HAP in the immobilization of heavy metals such as As should not be overestimated., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The efficient removal of ammonium nitrogen (NH 4 + -N) is vital to eliminating black and odorous water bodies. In this work, tidal flow constructed wetlands with gravel (TFCW-G) and with a mixture of zeolite and gravel (TFCW-Z) were set up to treat black and odorous water bodies at different hydraulic loading rates (HLRs). Results showed that zeolite significantly enhanced nitrogen removal, and the maximum NH 4 + -N removal efficiency of 96.69% was achieved in TFCW-Z at HLR of 3 m·d -1 with a flooding and drying cycle of 2 h. Zeolite addition changed the microbial community structure and the abundance of nitrification genes. Comammox Nitrospira was the only enriched strain accounting for NH 4 + -N removal in TFCW-G, while the co-occurrence of comammox Nitrospira and the canonical and potential ammonia-oxidizing bacteria were identified in TFCW-Z. Summarily, high performance, together with low footprint and low maintenance cost, are characteristics that make the TFCW-Z a promising and competitive alternative., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Bacteria commonly exhibit social activities through acyl-homoserine lactones (AHLs)-based quorum sensing (QS) systems to form their unique social network. The sigma factor RpoS is an important regulator that controls QS system in different bacteria. However, the upstream of RpoS involving regulation on QS system remains unclear. In Escherichia coli RpoS is regulated by stringent starvation protein A (SspA), which is dependent of histone-like nucleoid structuring protein (H-NS). To date, the connection between SspA and QS system is essentially unknown. Here, we characterized a typical LuxI/LuxR-type QS system in marine bacterium Pseudoalteromonas sp. T1lg65 which can produce four types of AHLs. The luxI encoding AHLs synthase and luxR encoding AHLs-responsive receptor are co-transcribed, providing advantages in rapidly amplifying QS signaling. Notably, SspA positively regulated luxI/luxR transcription by activating RpoS expression, which is mediated by H-NS. Interestingly, LuxR in turn positively regulated SspA expression. Therefore, SspA and QS system constitute a mutual positive regulation loop in T1lg65. In view of the crucial roles of SspA and QS system in environmental adaption, we believe that the improvement of bacterial tolerance to marine environments could be related to rapidly tuning SspA-involved QS programming., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Biofilm formation enhances the survival and persistence of microorganisms in response to environmental stresses. It has been revealed that stringent starvation protein A (SspA) can function as an important regulator dealing with environmental stresses for bacterial survival. However, the connection between SspA and biofilm formation is essentially unclear yet. In this study, we presented evidence showing SspA positively controls biofilm formation by up-regulating exopolysaccharides (EPS) production in marine bacterium Pseudoalteromonas sp. R3. Both qPCR and lacZ reporter system congruously revealed that SspA positively controls the expression of EPS biosynthesis gene cluster. Unlike generally accepted thought that SspA regulates bacterial physiology by inhibiting the expression of histone-like nucleotide structuring protein (H-NS) gene, the function of SspA on EPS production and biofilm formation in Pseudoalteromonas sp. R3 is H-NS-independent. Instead, SspA positively regulates the expression of sigma factor AlgU-encoding gene, thus affecting EPS biosynthesis and biofilm formation. In view of the important role of SspA in biofilm formation, we believe that the improvement of tolerance to marine environmental stresses could be related to tuning of SspA-involved biofilm formation., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Due to the high capacity of impurities in its structure, calcite is regarded as one of the most attractive minerals to trap heavy metals (HMs) and radionuclides via substitution during coprecipitation/crystal growth. As a high-reactivity mineral, calcite may release HMs via dissolution. However, the influence of the incorporated HMs and radionuclides in calcite on its dissolution is unclear. Herein, we reported the dissolution behavior of the synthesized calcite incorporated with cadmium (Cd), cobalt (Co), nickel (Ni), zinc (Zn), and uranium (U). Our findings indicated that the HMs and U in calcite could significantly change the dissolution process of calcite. The results demonstrated that the incorporated HMs and U had both inhibiting and enhancing effects on the solubility of calcite, depending on the type of metals and their content. Furthermore, secondary minerals such as smithsonite (ZnCO 3 ), Co-poor aragonite, and U-rich calcite precipitated during dissolution. Thus, the incorporation of metals into calcite can control the behavior of HMs/uranium, calcite, and even carbon dioxide.

Cadmium isotopic compositions in non-contaminated systems and anthropogenic sources of Cd generally have different isotopic signatures. Cadmium isotopes, as a novel tracer, can be useful for fingerprinting the anthropogenic Cd sources, providing a promising source tracing technique in environmental studies. This review presents: (i) analytical techniques for Cd isotopic composition; (ii) isotopic signatures of Cd derived from anthropogenic activities; (iii) isotopic compositions of Cd in the industrial-impacted environmental samples; (iv) cadmium isotopic fractionation induced by geochemical process. Finally, the perspectives of using Cd isotopic compositions in environmental studies are also briefly discussed., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Bacteria usually produce, release and detect quorum sensing (QS)-based signal molecules, and successively orchestrate gene expression in respond to environmental changes. Pseudoalteromonas are typical marine bacteria, but knowledge on their QS systems is extremely fragmentary. In this study, genome sequencing of Pseudoalteromonas sp. R3 was performed. Accordingly, a QS working model including three sets of hierarchically organized QS systems was proposed in strain R3. Among them, the typical LuxI/R-type QS system using acyl-homoserine lactones (AHLs) as signal molecules was characterized. Sequence similarity analysis indicated luxI encoding AHLs synthase is novel. The luxR encoding AHLs receptor is directly adjacent to luxI downstream. Notably, mutagenesis demonstrated LuxI and LuxR affect each other at transcriptional level, and both control the AHLs formation. Interestingly, it was found that LuxI/R-type QS system positively involves resistance to streptomycin. Thin-layer chromatography analysis showed strain R3 can produce 3-OH-C6-HSL and C8-HSL, which was supported by heterologous expression of LuxI in Escherichia coli. Sequence alignment analysis indicated that the N-terminal region of LuxI is more conservative than the C-terminal region, revealing the importance of N-terminal region in AHLs synthesis. The obtained findings enrich our knowledge on LuxI/R-type QS system in Pseudoalteromonas and its regulation on adaptation to marine environments., (Copyright © 2019 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)

This study presents a device for tracking, locating and communicating underwater vehicles as they work near the seabed. The system includes a base station placed on the seabed and a reflective module mounted on a hybrid underwater profiler (HUP). The base station localizes and communicates with the HUP working near the seabed based on laser reflections of corner cube retroreflectors. A tracking method based on the particle filter algorithm is then presented. Localization is performed using the least-squares method with refraction compensation. Lost tracking links are retrieved via a recovering approach based on the interpolation method. Finally, a communication method using a modulating retroreflector installed on the reflection module is proposed. The proposed tracking, localization, and communication approach provides higher localization accuracy with lower power consumption at low cost compared with the commonly used acoustic methods. The effectiveness of the proposed approach was clarified via tracking, localization, and communication experiments., Competing Interests: The authors declare no conflict of interest.

As one of the most toxic heavy elements, humans are mainly exposed to cadmium (Cd) via daily diets and smoking. Calcite can be used as an amendment directly or precipitated in situ based on microbial-induced carbonate precipitation (MICP) technology to immobilize Cd in soil with potential release of Cd due to calcite dissolution. Therefore, we converted microbial-induced calcite to less soluble hydroxyapatite and investigated the phase and morphology evolutions of the solids, as well as the immobilized efficiency, distribution and release of Cd. The results showed that the conversion of calcite to hydroxyapatite enhanced Cd removal efficiency up to 1.67% and 33.14% compared to the MICP process and adsorption by calcite, respectively. Accordingly, the released Cd decreased up to 94.10% and 99.96%, respectively. Our findings demonstrated that the conversion of calcite to hydroxyapatite might control the environmental behavior of heavy metals like Cd and can potentially be applied for soil remediation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The effects of interactions between and among chlorine (Cl), sulfur (S), phosphorus (P), and minerals on migration, transformation, and volatilization of zinc (Zn) were numerically simulated in sludge co-incineration using the chemical thermodynamic equilibrium method. Our results showed that all the minerals of Fe 2 O 3 , Al 2 O 3 , Fe 2 O 3 , and TiO 2 except for CaO in the sludge co-incineration system reacted with Zn which inhibited the Zn volatilization. The presence of S and P was beneficial to the formation of ZnSO 4 (s) and Zn 3 (PO 4 ) 2 (s). Cl weakened the chemical reactions between the minerals and Zn, thus increasing the Zn volatilization. Changes in Zn transformation and migration induced by the coupling of Cl + S were mainly controlled by Cl, S, and the minerals, while those induced by Cl + P and S + P were mainly controlled by P and S + P. The presence of P + Cl, S + Cl, S + P, S + Cl + P, Cl, and Al 2 O 3 in the coexisting mineral system controlled the reactions between the minerals and Zn., (© 2018 Water Environment Federation.)

A polyfluoroalkyl substituted phthalocyanine based supramolecular light switch was assembled by the host-guest interaction between the novel polyfluoroalkyl substituted silicon phthalocyanine and pyrene-β-cyclodextrin, which was attached on the sidewalls of SWNTs through the pyrene groups. This supermolecule can not only absorb light to convert its energy into heat energy, but also respond to light, control the release of phthalocyanine and restore fluorescence and produce singlet oxygen for a synergistic photothermal and photodynamic effect against Escherichia coli.

This paper presents a novel isobaric sample transfer apparatus developed to facilitate the continuous culture of microorganisms while also providing the capacity for maintaining the sample at in situ pressure during the whole transfer and culture process. This apparatus is fitted to the isobaric fluid sampler which is used for collecting the isobaric fluid sample. This apparatus can not only avoid decompression in traditional sample transfer but also realize the integrated function of sample transfer and culture under isobaric conditions. The subsampling cylinder can automatically work as a flow culture reactor after completing the subsampling of the pressurized sample. Several transfer experiments were carried out to demonstrate this design which can make the period of transfer automatically.

The low hydraulic loading rate (HLR) greatly restricts the wide application of subsurface wastewater infiltration system (SWIS) in densely populated areas. To increase the HLR, an innovative SWIS was developed using cyclic operation mode. In each cycle, a wastewater feeding period is followed by a drying period, in which the aeration is conducted by a medium-pressure fan. Results indicated that the removal rate of TOC and NH4(+)-N were more than 85% at HLR of 0.5m(3)/m(2)d, whereas the TN removal rate was lower than 20%, indicating that the aeration was efficient and denitrification process was largely limited in the SWIS. When HLR decreased from 0.5 to 0.2m(3)/m(2)d, the pollutant removal efficiency enhanced slightly except for TN. Overall, the intermittent operation and micro-power aeration, combined with shunting the pollutant loading were really helpful for SWIS to achieve higher HLR, which offers a reference for the design of innovative SWIS., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Twenty-four major and trace elements and the mineralogical composition of four sediment cores along the Pearl River and estuary were analyzed using ICP-AES, ICP-MS, and X-ray diffraction (XRD) to evaluate contamination levels. The dominant minerals were quartz, kaolinite, and illite, followed by montmorillonite and feldspars, while small amounts of halite and calcite were also observed in a few samples. Cluster analysis (CA) and principal component analysis (PCA) were performed to identify the element sources. The highest metal concentrations were found at Huangpu, primarily due to wastewater treatment plant discharge and/or the surreptitious dumping of sludge, and these data differed from those of other sources. Excluding the data from Huangpu, the PCA showed that most elements could be considered as lithogenic; few elements are the combination of lithogenic and anthropogenic sources. An antagonistic relationship between the anthropogenic source metals (K, Ba, Zn, Pb, Cd, Ag, Tl, and U) and marine source metals (Na, Mg, Ti, V, and Ca) was observed. The resulting normalized Al enrichment factor (EF) indicated very high or significant pollution of Cd, Ag, Cu, Zn, Mo, and Pb at Huangpu, which may cause serious environmental effects. Conflicting results between the PCA and EF can be attributed to the background values used, indicating that background values must be selected carefully.

Background: The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor-E2-related factor 2 (Nrf2)-antioxidant response element pathway serves a major function in endogenous cytoprotection in normal cells. Nrf2 is a transcription factor that mainly regulates the expression of a wide array of genes that produce the antioxidants and other proteins responsible for the detoxification of xenobiotics and reactive oxygen species. Nrf2 mediates the chemoprevention of cancer in normal cells., Results and Discussion: Growing body of evidence suggests that Nrf2 is not only involved in the chemoprevention of normal cells but also promotes the growth of cancer cells. However, the mechanism underlying the function of Nrf2 in oncogenesis and tumor protection in cancer cells remains unclear and thus requires further study., Conclusion: This review aims to rationalize the existing functions of Nrf2 in chemoprevention and tumorigenesis, as well as the somatic mutations of Nrf2 and Keap1 in cancer and Nrf2 cross talk with miRNAs. This review also discusses the future challenges in Nrf2 research.

Uranium compounds α-Ba2[UO2(PO4)2] (1), β-Ba2[UO2(PO4)2] (2), and Ba2[UO2(AsO4)2] (3) were synthesized by H3BO3/B2O3 flux reactions, though boron is not incorporated into the structures. Phases 1 and 2 are topologically identical, but 1 is heavily distorted with respect to 2. An unusual UO7 pentagonal bipyramid occurs in 1, exhibiting a highly distorted equatorial configuration and significant bending of the uranyl group, due to edge-sharing with one neighboring PO4(3-) tetrahedron. Compound 2 contains more normal square bipyramids that share corners with four neighboring PO4(3-) tetrahedra, but the uranyl cation UO2(2+) is tilted relative to the equatorial plane. Experimental evidence as well as density functional theory (DFT) calculations suggest that 1 is more stable than 2. In theory, 1 and 2 can interconvert by forming/releasing the shared edge between the uranyl polyhedron and the phosphate tetrahedron. Similar fundamental building blocks in β-Ba2[UO2(PO4)2] and Ba2[UO2(AsO4)2] indicate a possible evolution of uranyl-based structures from chain to layer type and formation of an accretional series.

Prolactin (PRL) is a pituitary polypeptide hormone characterized by multiple biological actions including stimulation of growth in the prostate, breast and ovarian epithelial cells. A sizable body of reports has presented evidences to indicate the involvement of PRL in the pathogenic process of cancers of the reproductive system, such as prostate and breast cancers. PRL exerts its effects by dimerizing its receptor (PRLR) on the plasma membrane, and initiating cellular Jak-Stat signal pathway. We have previously cloned from prostate cancer cells a natural variant of PRLR in which the S2 subdomain of the extracellular domain is missing (ΔS2). Our preliminary data showed that ΔS2 PRLR was able to dimerize and to constitutively activate the β-casein promoter (in the absence of its ligand, PRL) in breast and prostate epithelial cells. Enhancer of zeste homologue 2 (EZH2), an important histone-modifying enzyme, is able to trimethylate histone 3 on lysine 27 (H3K27Me3), consequently leading to gene silencing, especially silencing of tumor suppressor genes such as p53. We hypothesized that ΔS2 PRLR played an important pathogenic role in prostate cancer through, at least partly, alterations in the expression of EZH2 and the trimethylation of histone 3 on lysine 27. In the present study, overexpression of ΔS2 PRLR in prostate epithelial cells was achieved by infection with an adenoviral vector carrying the cDNA. The viable cell number overexpressing ΔS2 PRLR was assessed using MTS reagent. Western blot, chromatin immunoprecipitation (ChIP) assay and acid histone extraction were applied to detect expression of EZH2 as well as trimethylation of histone 3, respectively. In prostate epithelial cells, overexpression of ΔS2 PRLR increased the levels of EZH2 methyltransferase mRNA and protein, induced EZH2 methyltransferase recruitment to chromatin, increased the trimethylation of histone 3 on lysine 27, and decreased expression of the p53 gene. We concluded that ΔS2 PRLR plays an important pathogenic role in prostate cancer through epigenetic covalent modification leading to chromatin remodeling. Hypertrimethylation on H3K27 of the p53 gene promoter region due to elevated expression of ΔS2 PRLR by alternative splicing of the pre-mRNA in its full-length form might serve as a new mechanism underlying human prostate cancer.

Three novel uranyl borophosphates, Ag2(NH4)3[(UO2)2{B3O(PO4)4(PO4H)2}]H2O (AgNBPU-1), Ag(2-x)(NH4)3[(UO2)2{B2P5O(20-x)(OH)x}] (x = 1.26) (AgNBPU-2), and Ag(2-x)(NH4)3[(UO2)2{B2P(5-y)AsyO(20-x)(OH)x}] (x = 1.43, y = 2.24) (AgNBPU-3), have been prepared by the H3BO3-NH4H2PO4/NH4H2AsO4 flux method. The structure of AgNBPU-1 has an unprecedented fundamental building block (FBB), composed of three BO4 and six PO4 tetrahedra which can be written as 9□:[Φ] □<3□>□|□<3□>□|□<3□>□|. Two Ag atoms are linearly coordinated; the coordination of a third one is T-shaped. AgNBPU-2 and AgNBPU-3 are isostructural and possess a FBB of two BO4 and five TO4 (T = P, As) tetrahedra (7□:□<4□>□|□). AgNBPU-3 is a solid solution with some PO4 tetrahedra of the AgNBPU-2 end-member being substituted by AsO4. Only two out of the three independent P positions are partially occupied by As, resulting in site dependent isomorphism. The three compounds represent the first actinide borophosphates.

Three new potassium uranyl borates, K12[(UO2)19(UO4)(B2O5)2(BO3)6(BO2OH)O10] ·nH2O (TPKBUO-1), K4[(UO2)5(BO3)2O4]·H2O (TPKBUO-2), and K15[(UO2)18(BO3)7O15] (TPKBUO-3), were synthesized under high-temperature/high-pressure conditions. In all three compounds, the U/B ratio exceeds 1. Boron exhibits BO3 coordination only, which is different from other uranyl borates prepared at room temperature or under mild hydrothermal conditions. A rare uranium(VI) tetraoxide core UO4O2, which is coordinated by two BO3 groups, is observed in the structure of TPKBUO-1. Both structures of TPKBUO-1 and TPKBUO-3 contain three different coordination environments of uranium, namely, UO4O2, UO2O4, and UO2O5 and UO2O4, UO2O5, and UO2O6 bipyramids in TPKBUO-1 and TPKBUO-3, respectively.

Since reductive precipitation is considered as the most effective way to immobilize (79)Se, interaction of aqueous Se(IV)/Se(VI) with Fe(II)-bearing minerals has received extensive attention. In contrast to the thermodynamic calculations, as well as the prevalence of iron selenide phases observed in soil, sediments and ore deposits, most laboratory experiments have found that Se(0) was the reaction product. In this study, the interaction of Se(IV)/Se(VI) with FeSe/FeSe2 were investigated. The results demonstrate that FeSe and FeSe2 can be oxidized to Se(0) by Se(IV) with relatively fast kinetics, while reaction between Se(VI) and FeSe/FeSe2 only occurs under limited conditions (i.e. in the presence of high ferrous content and higher pH) with much slower kinetics, and there is no evident reaction in most case. Therefore, reduction of Se(IV) by Fe(II)-bearing minerals, in particular by natural occurring minerals, is envisioned to produce Se(0) at the early stage of experiments, rather than FeSe or FeSe2. Due to the formation of bulk Se(0) and its low solubility, the Fe-Se-O-H2O system will maintain redox disequilibrium in laboratory time-scale. This study also reveals that iron selenides, like iron sulfides, have strong reactivity toward Fe(3+). The findings in this study give insight into possible controls on Se redox process., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Total metal concentrations (Cr, Ni, Cu, Zn, and Pb), acid volatile sulfide and simultaneously extracted metals (AVS-SEM), and heavy metal fractionation were used to assess the heavy metals contamination status and ecological risk in the sediments of the Pearl River Estuary (PRE) and adjacent shelf. Elevated concentrations at estuarine sites and lower concentrations at adjacent shelf sites are observed, especially for Cu and Zn. Within the PRE, the concentration of heavy metals in the western shore was mostly higher than that in the middle shore. The metals from anthropogenic sources mainly occur in the labile fraction and may be taken up by organisms as the environmental parameters change. A combination of total metal concentrations, metal contamination index and sequential extraction analysis is necessary to get the comprehensive information on the baseline, anthropogenic discharge and bioavailability of heavy metals., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

An actinide borate phosphate was prepared via a high temperature solid-state reaction. This phase exhibits unprecedented complex inorganic nanotubular fragments with an external diameter of ~2 × 2 nm. The nanotubular aggregates are based on borate tubes where the exterior of the tubes is decorated with UO(2)(PO(4))(3) moieties to form a complex shape with a cross-section similar to the clover cross., (This journal is © The Royal Society of Chemistry 2012)

A neodymium borosilicate, Mg(2)Nd(13)(BO(3))(8)(SiO(4))(4)(OH)(3) (MgNdBSi-1), was obtained from a high-temperature (1400 °C), solid-state reaction under high-pressure conditions (4.5 GPa). MgNdBSi-1 contains six different types of Nd(3+) coordination environments with three different ligands: BO(3), SiO(4), and OH groups. Mg(2+) cations are only bond to BO(3) groups and form porous two-dimensional layers based on 12-membered ring fragments. Surprisingly, the OH groups are retained at high temperature and reside at the center of Mg-BO(3) rings.

Interaction of aqueous Se(IV) with pyrite was investigated using persistently stirred batch reactors under O2-free (<1 ppm) conditions at pH ranging from 4.5 to 6.6. Thermodynamic calculations, an increase in pH during the experiments, and spectroscopic observation indicate that the reduction of aqueous Se(IV) by pyrite is dominated by the following reaction: FeS2+3.5HSeO3−+1.5H+=2SO4(2−)+Fe2++3.5Se(0)+2.5H2O. The released Fe(II) was partitioned between the bulk solution and pyrite surface at pH≈4.5 and 4.8, with the Fe2+ density at pyrite-solution interface about 4 orders of magnitude higher than that in the bulk solution, while iron oxyhydroxide precipitated at pH≈6.6, resulting in the decrease of dissolved iron. In the Se(IV) concentration range of the experiments, aqueous Se(IV) reduction rate follows the pseudofirst order which is in the form of ln mSe(IV)=−k′t+ln mSe(IV)0, where k′ is apparent rate constant combining the rate constant k and pyrite surface area to mass of solution ratio (A/M). And the aqueous Se(IV) reduction rate constant for a standard system (k) with 1 m2 pyrite surface area per 1 kg solution was obtained to be 1.65×10(−4) h(−1), 3.28×10(−4) h(−1), and 4.76×10(−4) h(−1) at pH around 4.5, 4.8, and 5.1, respectively. The positive correlation between reaction rate and pH disagrees with the theories that protons are consumed when HSeO3− is reduced to Se0, and negative charge density on pyrite surface increases as pH increases. Thus, a ferrous iron mediated electron transfer mechanism is proposed to operate during the reduction of aqueous Se(IV) by pyrite. pH and iron concentration affect significantly on Se(IV) reaction rate and reaction product.

The simultaneous incorporation of IO3(-) and NpO2+ into Ba3(UO2)2(HPO4)2(PO4)2 (BaUP), which serves as a model for uranyl alteration phases, was investigated. LA-ICP-MS data demonstrate that the incorporation of both of these species is significantly enhanced when they are present together. The most probable explanation is that charge balance is obtained by the coupled substitutions of NpO2+ <--> UO2(2+) and IO3(-) <--> HPO4(2-). According to the LA-ICP-MS results, in the absence of iodate as much as 2.91 +/- 0.14 to 3.44 +/- 0.25% of the uranium in BaUP can be replaced by neptunium. When iodate is present in the reaction, the amount of uranium substitution by neptunium increases to 6.05 +/- 0.65% to 7.93 +/- 0.83%. The net increase for neptunium is 116 +/- 0.30% to 225 +/- 0.25%. Similarly, in the absence of NpO2+, iodate incorporation into BaUP reaches an I/U level of 0.0021 +/- 0.0004 to 0.0038 +/- 0.0005; whereas in its presence there is an increase to as much as 100 +/- 0.11% to 0.0042 +/- 0.0008.

Three new layered uranyl phosphates, Ba(3)(UO(2))(2)(HPO(4))(2)(PO(4))(2), Ba(UO(2))F(PO(4)), and Cs(2)(UO(2))(2)(PO(4))(2), were synthesized under mild hydrothermal conditions. These compounds serve as models for uranium alteration phases that might form when spent nuclear fuel is subjected to oxidizing groundwater containing dissolved phosphate. In order to address the possibility of the incorporation of the key fission product (129)I in the form of iodate into uranyl alteration phases, the substitution of IO(3)(-) for the structurally related PO(3)(OH)(2-) or PO(4)(3-) unit was probed. Iodate incorporation into these phases was investigated using LA-ICP-MS, and these data indicate incorporation of iodine with levels as high as 4162 ppm.

A key step in a chemoenzymatic process for the production of high-purity glycolic acid (GLA) is the enzymatic conversion of glycolonitrile (GLN) to ammonium glycolate using a nitrilase derived from Acidovorax facilis 72W. Protein engineering and over-expression of this nitrilase, combined with optimized fermentation of an E. coli transformant were used to increase the enzyme-specific activity up to 15-fold and the biocatalyst-specific activity up to 125-fold. These improvements enabled achievement of the desired volumetric productivity and biocatalyst productivity for the conversion of GLN to ammonium glycolate., ((c) 2007 Wiley Periodicals, Inc.)

Hydroxycarboxylic acid monomers can be used to prepare industrially important polymers. Enzymatic production of such hydroxycarboxylic acids is often preferred to chemical production since the reactions are run at ambient temperature, do not require strongly acidic or basic reaction conditions, and produce the desired product with high selectivity at high conversion. However, native enzymes often do not perform desired reactions with the efficiency required for commercial applications. Protein engineering was used to significantly increase the specific activity of nitrilase from Acidovorax facilis 72W for the conversion of 3-hydroxyvaleronitrile to 3-hydroxyvaleric acid. Overexpression of engineered nitrilase enzymes in Escherichia coli, combined with immobilization of whole cells in alginate beads that can be recycled many times has facilitated the development of a commercially viable bioprocess for production of 3-hydroxyvaleric acid., ((c) 2006 Wiley Periodicals, Inc.)

The genes encoding a thermally stable and regio-selective nitrile hydratase (NHase) and an amidase from Comamonas testosteroni 5-MGAM-4D have been cloned and sequenced, and active NHase has been over-produced in Escherichia coli. Maximal activity requires co-expression of a small open reading frame immediately downstream from the NHase beta subunit gene. Compared to the native organism, the E. coli biocatalyst has nearly threefold more NHase activity on a dry cell weight basis, and this activity is significantly more thermally stable. In addition, this biocatalyst converts a wide spectrum of nitrile substrates to the corresponding amides. Such versatility and robustness are desirable attributes of a biocatalyst intended for use in commercial applications.