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2D carbon ribbon/Al2O3 was synthesized with two-dimensional metal organic frameworks 2D-MOFs as precursors using the solvothermal and calcination methods. Batch experiments of adsorption parameters such as pH, liquid/solid ratio, adsorption kinetics, adsorption thermodynamics, and anions competitions were investigated to understand the adsorptive behavior of fluoride on carbon ribbon/Al2O3 and nitrogen-doped carbon ribbon/Al2O3. The adsorption of fluoride on carbon ribbon/Al2O3 could be described as the chemical and multilayer adsorption, while the adsorption of fluoride on nitrogen-doped carbon ribbon/Al2O3 followed the chemical and monolayer adsorption phenomenon. The fluoride on nitrogen-doped carbon ribbon/Al2O3 had a much faster adsorption rate of 3.1×10−7 m/s than carbon ribbon/Al2O3, which was 1.2×10−7 m/s. The nitrogen-doping on carbon ribbon enhances structural defects and improves the adsorption performance of fluoride. Also, the diacetylene linkages (—C≡C—) and pyridinic-N were studied to understand their influences on removing fluoride. The result indicates that carbon ribbon and nitrogen-doped ribbon could serve as good adsorbents for removing fluoride.

Multiple alleles were constantly detected in Alternaria solani isolates by simple sequence repeat (SSR) analysis, and sectors were also observed in their subcultures. These preliminary results and observations point to a possible parasexual cycle in A. solani. In this study, codominant SSR markers were used as molecular markers on the chromosomes of A. solani and single-conidium subculture was used to simulate the mitosis process of A. solani in nature. The number of alleles at locus As-95236 changed from 2 to 1 as a molecular marker for haploidy of parasexuality of A. solani. Fifty monosporic F1 strains were tested. The results showed that two parent strains lost allele with a haploid probability of 38%. For F2 strains, the results showed that all four F1 strains lost allele with a haploid probability of 75%. Since sexual recombination of A. solani has not been found so far, the allele lost in the subcultures of A. solani isolates provides molecular evidence for the existence of parasexual reproduction in A. solani.

Tinea capitis is a type of dermatophyte infection primarily affecting children. We report a case of an elderly woman with well-controlled diabetes mellitus presenting with a six-month history of erythema with yellow crusts on her scalp and extensive erythematous patches with scales on the body skin. She adopted a stray cat before the disease onset. Dermoscopic findings and manifestation under the Wood’s lamp favoured the diagnosis of tinea capitis. Further microscopic examinations of her scalp, including direct KOH and fluorescence stain examination, fungal culture and polymerase chain reaction sequencing identification confirmed the diagnosis of tinea capitis caused by Microsporum canis. Treatment with oral terbinafine was effective. Adult tinea capitis is often misdiagnosed due to its rarity and atypical presentation. However, in some regions, the incidence of tinea capitis in immunocompetent adults is rising which requires the awareness of clinicians. A thorough history (including the animal contacting history), physical examination and further mycological examinations are required for diagnosis. Trichophyton violaceum is the most common dermatophyte species in most regions while adult tinea capitis caused by Microsporum canis is less common. Terbinafine, griseofulvin and itroconazole have been reported to be effective drugs for the treatment of tinea capitis, and terbinafine can be considered as systemic treatment in elderly patients with comorbidities to reduce the drug–drug interaction.

The MIL-53(Al)-NH2 was designed to remove fluoride with hierarchical hollow morphology. It was used as an adsorbent for fluoride removal at a wide pH range (1-12) due to the positive zeta potential of MIL-53(Al)-NH2. The pH did not significantly influence the fluoride adsorption into MIL-53(Al)-NH2. However, the adsorbent indicated good adsorption capacity with maximum adsorption of 1070.6 mg g-1. Different adsorption kinetic and thermodynamic models were investigated for MIL-53(Al)-NH2. The adsorption of fluoride into MIL-53(Al)-NH2 followed the pseudo-second-order model and a well-fitted Langmuir model indicating chemical and monolayer adsorption process. When mass transfer model was used at initial concentrations of 100 ppm and 1000 ppm, the rates of conversion were 8.4 × 10-8 and 4.7 × 10-8 m s-1. Moreover, anions such as [Formula: see text], [Formula: see text], [Formula: see text], Cl-, and Br- also had less effect on the adsorption of fluoride. Also, experimental and theoretical calculations on adsorption mechanism of MIL-53(Al)-NH2 revealed that the material had good stability and regenerative capacity using alum as regenerant. In a nutshell, the dominant crystal face (1 0 1) and adsorption sites Al, O, and N combined well with F-, HF, and HF2- through density functional theory. It opens a good way of designing hollow MOFs for adsorbing contaminants in wastewater.

International audience; Thermococcus gammatolerans is anaerobic euryarchaeon which grows optimally at 88 °C and its genome encodes a family B DNA polymerase (Tga PolB). Herein, we cloned the gene of Tga PolB, expressed and purified the gene product, and characterized the enzyme biochemically. The recombinant Tga PolB can efficiently synthesize DNA at high temperature, and retain 93% activity after heated at 95 °C for 1.0 h, suggesting that the enzyme is thermostable. Furthermore, the optimal pH for the enzyme activity was measured to be 7.0–9.0. Tga PolB activity is dependent on a divalent cation, among which magnesium ion is optimal. NaCl at low concentration stimulates the enzyme activity but at high concentration inhibits enzyme activity. Interestingly, Tga PolB is able to efficiently bypass uracil in DNA, which is distinct from other archaeal family B DNA pols. By contrast, Tga PolB is halted by an AP site in DNA, as observed in other archaeal family B DNA polymerases. Furthermore, Tga PolB extends the mismatched ends with reduced efficiencies. The enzyme possesses 3′-5′ exonuclease activity and this activity is inhibited by dNTPs. The DNA binding assays showed that Tga PolB can efficiently bind to ssDNA and primed DNA, and have a marked preference for primed DNA. Last, Tga PolB can be used in routine PCR.

A superb adsorbent for Cr(VI) removal with a high adsorption capacity and acidic resistance was facilely synthesized via in situ hydrothermal cross-linking and reduction reaction of poly-Schiff base using m-phenylenediamine and glutaraldehyde as feedstock. The hydrothermal process effectively facilitated the condensation between aldehyde and amine group to strengthen the chemical structure by cross-linking the polymeric chains. Morphological evolution of the polymer via disaggregation and reassembly to finally form regular core–shell configuration was observed. The produced nanoparticles possess the excellent adsorption performance (833.3 mg g−1), far beyond most of the reported adsorbents, and exhibit fine reusability. The possible adsorption mechanism can be attributed to Cr(VI) electrostatic adsorption followed by redox reaction and chelation.

Since hyperthermophilic Archaea (HA) thrive in high-temperature environments, which accelerate the rates of deamination of base in DNA, their genomic stability is facing a severe challenge. Hypoxanthine (Hx) is one of the common deaminated bases in DNA. Generally, replication of Hx in DNA before repaired causes AT → GC mutation. Biochemical data have demonstrated that 3-methyladenine DNA glycosylase II (AlkA) and Family V uracil DNA glycosylase (UDG) from HA could excise Hx from DNA, thus triggering a base excision repair (BER) process for Hx repair. Besides, three endonucleases have been reported from HA: Endonuclease V (EndoV), Endonuclease Q (EndoQ), and Endonuclease NucS (EndoNucS), capable of cleaving Hx-containing DNA, thereby providing alternative pathways for Hx repair. Both EndoV and EndoQ could cleave one DNA strand with Hx, thus forming a nick and further initiating an alternative excision repair (AER) process for the follow-up repair. By comparison, EndoNucS cleaves both strands of Hx-containing DNA in a restriction endonuclease manner, thus producing a double-stranded break (DSB). This created DSB might be repaired by homologous recombination (HR) or by a combination activity of DNA polymerase (DNA pol), flap endonuclease 1 (FEN1), and DNA ligase (DNA lig). Herein, we reviewed the most recent advances in repair of Hx in DNA triggered by DNA glycosylases and endonucleases from HA, and proposed future research directions.

Traditional 3D printing materials are not suitable for tissue engineering due to their toxicity, low degradability and poor biocompatibility. In this study, a new amphiphilic biodegradable waterborne polyurethane (WBPU) was developed by a green and sustainable process without any organic solvents, catalysts or cross-linkers. The soft segments of this kind of WBPU were formed by replacing hydrophobic poly(e-caprolactone) diol with hydrophilic poly(ethylene glycol) (PEG). Different block lengths of PEG were used for this purpose. The combination of ester and ether groups endowed WBPU with amphiphilic characteristics, which is important for regeneration and maintenance of tissue. The effects of composition and content of soft segments on the phase separation, thermal properties, mechanical properties, water absorption, biodegradability and cytotoxicity of WBPU were investigated. The results showed that the desired properties of WBPU could be achieved by tuning the block length of PEG and content of soft segments. The present work provided a new approach to prepare WBPUs with amphiphilic and biodegradable characteristics, which are promising candidates for 3D printing materials for tissue engineering scaffolds.

8-oxoguanine (GO) is a major lesion found in DNA that arises from guanine oxidation. The hyperthermophilic and radioresistant euryarchaeon Thermococcus gammatolerans encodes an archaeal GO DNA glycosylase (Tg-AGOG). Here, we characterized biochemically Tg-AGOG and probed its GO removal mechanism by mutational studies. Tg-AGOG can remove GO from DNA at high temperature through a β-elimination reaction. The enzyme displays an optimal temperature, ca.85–95 °C, and an optimal pH, ca.7.0–8.5. In addition, Tg-AGOG activity is independent on a divalent metal ion. However, both Co2+ and Cu2+ inhibit its activity. The enzyme activity is also inhibited by NaCl. Furthermore, Tg-AGOG specifically cleaves GO-containing dsDNA in the order: GO:C, GO:T, GO:A, and GO:G. Moreover, the temperature dependence of cleavage rates of the enzyme was determined, and from this, the activation energy for GO removal from DNA was first estimated to be 16.9 ± 0.9 kcal/mol. In comparison with the wild-type Tg-AGOG, the R197A mutant has a reduced cleavage activity for GO-containing DNA, whereas both the P193A and F167A mutants exhibit similar cleavage activities for GO-containing DNA. While the mutations of P193 and F167 to Ala lead to increased binding, the mutation of R197 to Ala had no significant effect on binding. These observations suggest that residue R197 is involved in catalysis, and residues P193 and F167 are flexible for conformational change.

The high level of fluorine and low sulfur in the ore could significantly undermine the bioleaching effectiveness. Here, a strategy to improve the bioleaching efficiency by introducing fluoride-resistant mesophilic eosinophils coupled with pyrite supplement was investigated in a bioleaching system with such ore. The results of column and heap bioleaching showed that 89.25% and 90.40% of uranium were recovered with the consortium and pyrite addition, which increased the uranium leaching rates by 13.22% and 8.96% as compared with the sulfuric acid leaching. Hence, it provides a method to improve uranium bioleaching efficiency of the high-fluorine and low-sulfur uranium ore by the consortium adding pyrite.

Development of efficient, green and low-cost natural mineral-based reductive materials is promising to remediation of hexavalent chromium(Cr(VI))-contaminated soil. Considering the synergetic effect between pyrite and zerovalent iron (ZVI), an activated pyrite supported ZVI(ZVI/FeS2) with high reducing activity was developed by ball milling activation of natural pyrite and sulfidation of ZVI. The remediation property of ZVI/FeS2 for Cr(VI)-contaminated soil was evaluated with different ZVI/FeS2 dosage, soil-water ratio, initial pH, time and temperature, as well as the stability of Cr. The results showed that ZVI/FeS2 possessed high reduction activity with soil Cr(VI) removal rate up to 99 % even under alkaline condition, and soil with different pH values eventually converged to neutral after 90 days, indicating that ZVI/FeS2 has a good self-regulating alkaline ability. The reduction process conformed to Langmuir-Hinshelwood first-order kinetics and was a spontaneous and endothermic process. The lower activation energy of 17.97 kJ mol−1 (usually 60–250 kJ mol−1) indicated that the reduction reaction of Cr(VI) was particularly easy to occur. The speciation change of Cr in soil within 30 days demonstrated that the Cr in the soil was converted from a readily migratable state to a more stable state, where the Fe–Mn oxide bound fraction reached 85.03 % due to the generation of Cr(III)/Fe(III) co-precipitation. The results of long-term stability experiments showed that the leaching concentrations of Cr(VI) and total Cr decreased significantly after the ZVI/FeS2 treatment and remained stable at very low levels for 180 days. This study provided a sustainable way to fully utilize natural pyrite minerals to obtain iron-bearing reductive materials for feasible, effective and long-term stable immobilization of Cr(VI) in soil.

The potato early blight was caused by Alternaria solani (Aso). At present, potato early blight resistant varieties are lacking. The experiment of Aso inoculation on a.k.a. Favorita showed that the content of chlorophyll decreased continuously within 2 days after inoculation. In addition, the contents of JA-Ile, SA, ABA and IAA were determined by LC-MS.The results of two defense-related hormones showed that jasmonic acid content decreased significantly, while jasmonic acid content did not change significantly. In order to understand the difference in gene expression of potatoes infected by Aso, the 24 hpi, 36 hpi and 48 hpi transcriptome were determined. The results showed that the gene annotation and cluster analysis of DEGs revealed a variety of defense responses to Aso infection, especially the plant hormone signal transduction pathway. The differential expression of 10 DEGs was confirmed by qPCR analysis. Finally, through weighted gene co-expression network analysis (WGCNA), “samonl” was determined as a key hormone-related network in the process of Aso infection in potatoes. This study provides an important clue for understanding the interaction between potato and Aso and for disease resistance breeding.

International audience; Hyperthermophilic Archaea (HA) thrive in high temperature environments and their genome is facing severe stability challenge due to the increased DNA damage levels caused by high temperature. Surprisingly, HA display spontaneous mutation frequencies similar to mesophilic microorganisms, thereby indicating that the former must possess more efficient DNA repair systems than the latter to counteract the potentially enhanced mutation rates under the harsher environment. Although a few repair proteins or enzymes from HA have been biochemically and structurally characterized, the molecular mechanisms of DNA repair of HA remain largely unknown. Genomic analyses of HA revealed that they lack MutS/MutL homologues of the mismatch repair (MMR) pathway and the recognition proteins of the nucleotide excision repair (NER) pathway. Endonucleases play an essential role in DNA repair. NucS endonuclease, a novel endonuclease recently identified in some HA and bacteria, has been shown to act on branched, mismatched, and deaminated DNA, suggesting that this endonuclease is a multifunctional enzyme involved in NER, MMR, and deaminated base repair in a non-canonical manner. However, the catalytic mechanism and the physiological function of NucS endonucleases from HA need to be further clarified to determine how they participate in the different DNA repair pathways in cells from HA. In this review, we focus on recent advances in our understanding of the function of NucS endonucleases from HA in NER, MMR, and deaminated DNA repair, and propose directions for future studies of the NucS family of endonucleases.

We investigated the adsorption mechanisms for removing fluoride based on experimental and modeling studies. Lanthanum-aluminum perovskite was designed for treating wastewater contaminated by fluoride. A fluorine-species model was developed to calculate the concentrations of different species of fluorine: F−, HF, HF2−. Multiple kinetic models were examined and the pseudo-second order model was found the best to fit the experimental data, implying fast-chemisorption. The thermodynamic data were fitted by the Langmuir model and Freundlich model at different temperatures, indicating heterogeneous adsorption at low temperature and homogeneous adsorption at high temperature. The La2Al4O9 material had less influence from negative ions when adsorbing fluoride. The adsorption mechanisms were further studied using experiments and Density Functional Theory calculations. The adsorption experiments could be attributed to the lattice plane (1 2 1) and La, O, Al sites. More Al sites were required than La sites for the increase of fluoride concentration. By contrast, more La sites than Al sites were needed for increased pH.

A synthetic method was developed to prepare biodegradable waterborne polyurethanes (BHPUs) with a high solid content by introducing different molecular weights of poly(ethylene glycol) (PEG) into poly(e-caprolactone) (PCL)-based polyurethanes. PCL is a semi-crystalline polymer that can be degraded in lipase to prepare biodegradable waterborne polyurethanes. The biodegradability of BHPUs was evaluated, and the results showed that BHPU samples could be degraded in a solution of phosphate-buffered saline (PBS)/lipase but not in PBS. Two different synthesis routes were used to prepare the BHPUs, which resulted in different association relationships between the ionic hydrophilic polymer dimethylol propionic acid (DMPA) and a nonionic hydrophilic polymer (PEG). The influence of the association relationship between DMPA and PEG on the solid content and other BHPU properties was investigated. The results showed that the method of associating all PEG molecules with DMPA increased the crystallization, tensile properties, and water and soil repellency of the BHPU samples. The solid content of the BHPU samples increased from 41% to 52.7%. In addition, PEG with molecular weights of 400 g mol−1 and 1000 g mol−1 had the best effect on the dispersibility and stability of BHPU samples when incorporated into a polyurethane backbone.

Here, a nanofiber-exfoliated bacteria cellulose aerogel with improved water affinity and high mass transfer was synthesized. Consequently, poly Schiff base can be uniformly coated within the body of bacteria cellulose aerogel without the traditional dispersion treatment. The composite aerogel has adequate mechanical and thermal stability and high mass transfer efficiency. Such an aerogel can serve as a superior adsorbent for flow through adsorption of pollution. Typically, the adsorption capacity towards Cr(VI), Cu(II), Re(VII), Conga red, and Orange G reaches as high as 321.5, 256.4, 153.8, 333.3, and 370.3 mg g&minus, 1, respectively. Moreover, the adsorption by this composite aerogel is very fast, such that, for example, at just 2 s, the adsorption is almost finished with Cr(VI) adsorption. Moreover, the composite aerogel exhibits a good adsorption-desorption capability. This research will hopefully shed light on the preparation of bacteria cellulose-derived macroscopic materials powerful in not only environmental areas, but also other related applications.

International audience; The hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 encodes two uracil DNA glycosylases (UDGs): Tba UDG247 and Tba UDG194. Herein, we characterized biochemically Tba UDG194. Compared with Tba UDG247, Tba UDG194 exhibits different biochemical characteristics. At >85 °C, >90 cleavage percentage was observed, suggesting that Tba UDG194 can remove uracil from DNA at physiological temperature of its host. Thus, the enzyme is the most thermophilic glycosylase among all the reported UDGs. Furthermore, the optimal pH of the enzyme activity was estimated to be 10, which is higher than that of Tba UDG247. Similar to Tba UDG247, Tba UDG194 activity is independent on a divalent metal ion. Mn2+, Zn2+ and Cu2+ display inhibitory effect on the enzyme activity at varied degreed whereas Mg2+ and Ca2+ have no detectable effect on the enzyme activity. In addition, Tba UDG194 is a salt-tolerant enzyme that retains compromised activity at 600 mM NaCl. Furthermore, Tba UDG 194 displays the following substrate preference: U ≈ U/G > U/T > U/A > U/C. The Arrhenius activation energy was estimated to be 20.1 ± 3.4 kcal/mol, theoretically representing the energy barrier for uracil removal from DNA by Tba UDG194. Overall, our observations suggest that Tba UDG194 might be involved in removal of uracil in DNA in Thermococcus cells.

International audience; Recent studies show that NucS endonucleases participate in mismatch repair in several archaea and bacteria. However, the function of archaeal NucS endonucleases has not been completely clarified. Here, we describe a NucS endonuclease from the hyperthermophilic and radioresistant archaeon Thermococcus gammatolerans (Tga NucS) that can cleave uracil (U)-and hypoxanthine (I)-containing dsDNA at 80°C. Biochemical evidence shows that the cleavage sites of the enzyme are at the second phosphodiester on the 5′-site of U or I, and at the third phosphodiester on the 5′-site of the opposite base of U or I, creating a double strand break with a 4-nt 5′-overhang.The ends of the cleaved product of Tga NucS are ligatable, possessing 5′-phosphate and 3′-hydroxyl termini, which can be utilized by DNA repair proteins or enzymes. Tga NucS displays a preference for U/G-and I/T-containing dsDNA over other pairs with U or I, suggesting that the enzyme is responsible for repair of U and I in DNA that arise from deamination. Biochemical characterization of cleaving U-and I-containing DNA by Tga NucS was also investigated. The DNA-binding results show that the enzyme exhibits a higher affinity for normal, U-and I-containing dsDNA than for normal, U-and I-containing ssDNA. Therefore, we present an alternative pathway for repair of deaminated bases in DNA triggered by archaeal NucS endonuclease in hyperthermophilic archaea.

Here, Pannonibacter phragmitetus BB was investigated at genomic, genetic and protein levels to explore molecular mechanisms of chromium biotransformation, respectively. The results of Miseq sequencing uncovered that a high-qualified bacterial genome draft was achieved with 5.07 Mb in length. Three novel genes involved in chromate reduce and transport, named nitR, chrA1 and chrA2, were identified by alignment, annotation and phylogenetic tree analyses, which encode a chromate reductase (NitR) and two chromate transporters (ChrA1 and ChrA2). Reverse transcription real-time polymerase chain reaction (RT-qPCR) analyses showed that the relative quantitative transcription of the three genes as the maximum reduction rate of Cr(VI) were significantly up-regulated with the increasing initial Cr(VI) concentrations. However, at the maximum cell growth points nitR was in a low transcription level, while the transcription of chrA1 and chrA2 were hold at a relatively high level and decreased with the increasing initial Cr(VI) concentrations. The ex-situ chromate reducing activity of NitR was revealed a Vmax of 34.46 µmol/min/mg enzyme and Km of 14.55 µmol/L, suggesting feasibility of the reaction with Cr(VI) as substrate. The multiple alignment demonstrates that NitR is potentially a nicotinamide adenine dinucleotide phosphate (NADPH) dependent flavin mononucleotide (FMN) reductase of Class I chromate reductases. Our results will prompt a large-scaled bioremediation on the contaminated soils and water by Pannonibacter phragmitetus BB, taking advantage of uncovering its molecular mechanisms of chromium biotransformation.

Many kinds of adsorbents have been developed for removing fluoride from water. However, the unclear actual mechanism of fluoride adsorption greatly restricts the structural design and application of novel adsorbents. Based on the understanding of the interaction between hydroxyl and fluoride, a novel core-shell nanostructure of boehmite was synthesized via an in-situ-induced assembly for removing fluoride. The formed polycrystalline boehmite (γ-AlOOH) nanostructure significantly enhances adsorption performance. The transformation of fluoride forms (including F−, HF, HF2−) is closely related to the solution property. The acidic solution is more favorable, mainly because of the conversion of HF (pyrazine) and HF2− (the bifluoride ion) with a strong hydrogen bond effect from fluoride (F−) with pH

A novel efficient adsorbent of bacterial cellulose/poly(m-phenylenediamine (BC/PmPD) was prepared for Cr(VI) removal by combining the advantages of high adsorption capacity of PmPD and easy reclamation of BC. Through monomer (mPD) pre-adsorption on BC, the stable hybrid structure of PmPD nanoparticles functionalization on BC fibril was successfully realized by in-situ oxidative polymerization of adsorbed mPD. The morphology and structure of the adsorbents were analyzed by SEM, TEM, XRD, FTIR, and XPS techniques. The interaction between BC and PmPD and adsorption mechanism were also analyzed. The optimized BC/PmPD has Langmuir Cr(VI) adsorption capacity of 434.78 mg/g, much higher than many reported adsorbents. The Cr(VI) adsorption on BC/PmPD was ascribed to the Cr(VI) adsorption on protonated NH and NH2 groups and the redox reaction of Cr(VI) to Cr(III) by the reduction of amine, followed by Cr(III) chelation on imino groups of PmPD. The recycling test indicated that the BC/PmPD has good regeneration and reusability capacity with its fast-reversible macroscopic assembly and disassembly features, and high stabilization of PmPD on BC. Findings in the present study demonstrated that the BC/PmPD can be considered as a promising adsorbent for Cr(VI) removal due to its high adsorption capacity, efficient reclamation, good regeneration performance.

Overpressure blast-wave induced brain injury (OBI) and its long-term neurological outcome pose significant concerns for military personnel. Our aim is to investigate the mechanism of injury due to OBI.Rats were divided into 3 groups: (1) Control, (2) OBI (exposed 30psi peak pressure, 2-2.5ms), (3) Repeated OBI (r-OBI) (three exposures over one-week period). Lung and brain (cortex and cerebellum) tissues were collected at 24h post injury.The neurological examination score was worse in OBI and r-OBI (4.2±0.6 and 3.7±0.5, respectively) versus controls (0.7±0.2). A significant positive correlation between lung and brain edema was found. Malondialdehyde (index for lipid peroxidation), significantly increased in OBI and r-OBI groups in cortex (p0.05) and cerebellum (p0.01-0.001). The glutathione (endogenous antioxidant) level decreased in cortex (p0.01) and cerebellum (p0.05) of r-OBI group when compared with the controls. Myeloperoxidase activity indicating neutrophil infiltration, was significantly (p0.01-0.05) elevated in r-OBI. Additionally, tissue thromboplastin activity, a coagulation marker, was elevated, indicating a tendency to bleed. NGF and NF-κB proteins along with Iba-1 and GFAP immunoreactivity significantly augmented in the frontal cortex demonstrating microglial activation. Serum biomarkers of injury, NSE, TNF-alpha and leptin, were also elevated.OBI triggers both inflammation and oxidative injury in the brain. This data in conjunction with our previous observations suggests that OBI triggers a cascade of events beginning with impaired cerebral vascular function leading to ischemia and chronic neurological consequences.

It is a challenge to simultaneously treat the combined pollutants of chromium(VI) (Cr(VI)) and organics (such as phenol) in wastewater. Here, a stable and efficient redox system based on FeS2 sulfidated zero valent iron (FeS2/Fe0) and persulfate (PS) was developed to synchronously remove Cr(VI) and phenol. 100% of phenol (10 mg/L) was oxidized in 10 min and Cr(VI) (20 mg/L) was completely reduced to Cr(III) in 90 min in the FeS2/Fe0+PS system with a pH range of 3.0–9.0, respectively. phenol was selectively oxidized without re-oxidizing Cr(III) in such system. The surface-bound Fe2+ was the major reactive species to synchronously reduce Cr(VI) and oxidize phenol. The mechanisms were elucidated that the phenol degradation was accelerated by the generated Cr(III) complexing with its products, and that SO42−, whose production speed was accelerated by the PS activation to oxidize phenol and FeS2, was conductive to corrode Fe0 to regenerate the surface-bound Fe2+ for reducing Cr(VI) and oxidizing phenol. It is potential to develop a high-performance and large-scaled FeS2/Fe0-based redox platform to remediate the complex pollution of Cr(VI) and organics.

Chemical reduction of Cr(VI) to Cr(III) by reductive materials is the most widely used technology for the remediation of Cr(VI)-contaminated soil due to its high efficiency, adaptability and low cost. This paper reviews chromium chemistry and the materials that can effectively reduce Cr(VI) to Cr(III) for the remediation of Cr(VI)-contaminated soil, namely iron-bearing reductants, sulfur-based compounds and organic amendments. Moreover, we discuss the corresponding mechanisms involved in the process of immobilization of Cr(VI) in polluted soil, and emphasize the relationship between the materials remediation performance and soil environmental conditions. Besides, perspectives on the potential future researches of novel materials design and technological development in the remediation of Cr(VI) contaminated soil are also put forward.

Here, a novel strategy that combines microbial oxidation by As(III)-oxidizing bacterium and biogenic schwertmannite (Bio-SCH) immobilization was first proposed and applied for treating the highly arsenic-contaminated soil. Brevibacterium sp. YZ-1 isolated from a highly As-contaminated soil was used to oxidize As(III) in contaminated soils. Under optimum culture condition for microbial oxidation, 92.3% of water-soluble As(III) and 84.4% of NaHCO3-extractable As(III) in soils were removed. Bio-SCH synthesized through the oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans immobilize As(V) in the contaminated soil effectively. Consequently, the combination of microbial oxidation and Bio-SCH immobilization performed better in treating the highly As-contaminated soil with immobilization efficiencies of 99.3% and 82.6% for water-soluble and NaHCO3-extractable total As, respectively. Thus, the combination can be considered as a green remediation strategy for developing a novel and valuable solution for As-contaminated soils.

Introduction It remains unclear whether exposure to repeated positive acceleration (+Gz) can exacerbate endothelial dysfunction on the basis of hyperlipidemia. The aim of this study was to investigate the effect of repeated +Gz exposure on endothelial function in high-fat-diet-induced hyperlipidemic rats. Material and methods Male Sprague-Dawley rats were randomly divided into control, repeat +Gz exposure, high-fat diet (HFD), and +Gz + HFD groups. The rats in the +Gz group were exposed to +Gz and the rats in the HFD group were fed a diet with 2% cholesterol. The rats in the +Gz + HFD group received both the +Gz exposure and HFD. Eight weeks later, the endothelium-dependent relaxation of the aorta was tested and the ultrastructure of the endothelial cells was observed using transmission electron microscopy. Quantitative real-time polymerase chain reaction and Western blot were used to detect the mRNA and protein expression of endothelial function-associated proteins. Results Repeated +Gz exposure elevated the serum level of LDL-C in HFD rats. In the +Gz + HFD rats, the ACh-induced relaxation in the aorta rings was significantly attenuated and the endothelial cells of the aorta were dramatically damaged compared with HFD rats. Nitric oxide content and eNOS expression in the aortic tissue were markedly decreased and the oxidative stress was more serious in the +Gz + HFD rats compared with HFD rats. In addition, repeated +Gz exposure significantly increased serum ox-LDL level and LOX-1 expression in the aorta of HFD rats, thereby activating NF-κB p65 and upregulating the expression of interleukin 6, ICAM-1 and VAP-1. Conclusions Repeated +Gz exposure promotes endothelial dysfunction in HFD-induced hyperlipidemic rats.

Hexavalent ferrate, Fe(VI), is a promising oxidation–coagulation dual–functional reagent for removing aromatic contaminants (ACs) in water engineering systems. Recognizing that an increasing number of ACs are being used and introduced to the engineered waters, experimental measurements of the Fe(VI) oxidation kinetics, especially apparent second–order rate constants (kapp) are relatively expensive for these numerous organic compounds. Therefore, reliable models are highly demanded for predicting kapp of Fe(VI) oxidation of ACs with wide structural diversity and reactivity. In the present study, a quantitative structure–activity relationship (QSAR) model was developed for the kapp predication at pH = 7 using stepwise multiple linear regression analysis (MLR) with the training set (n = 26). The standardized QSAR model was obtained: lnkapp = 34.7 − 4.80 × IP, where IP is the ionization potential. The internal ( Q LOO 2 = 0.81, n = 26) and external validation ( Q ext 2 = 0.82, n = 8) indicates a robust prediction for kapp. Further, we compared the predicted kapp with experimental k values for Fe(VI) oxidation of phenolic compounds, and demonstrated that possible first step reaction pathways depends on different electron donating/withdrawing abilities of the functional groups, corroborating the mechanistic meaning of IP in the QSAR model. The QSAR model developed is helpful in understanding the degradation mechanisms of ACs by Fe(VI), and the predicted kapp values provide a basis to optimize the Fe(VI) oxidation of ACs during wastewater treatment processes.

A polymeric hydroxyl ferric phosphate (PHFP) was prepared by using a byproduct of titanium dioxide containing ferrous sulfate and phosphates under alkaline condition. The PHFP was used to immobilize lead (Pb) and cadmium (Cd) in soils. Fourier transform infrared spectra, X-ray diffraction were applied to revealing the characteristics of PHFP, and the modified Tessier sequential extraction and column leaching experiment with simulated acid rain were used to assess the effectiveness of immobilization of Cd and Pb in soils by PHFP. The results showed that PHFP was indeed a polymer with complicated OH—Fe—P structure and consisted of Fe6(OH)5(H2O)4(PO4)4(H2O)2 and Fe25(PO4)14(OH)24. Moreover, the removal rates of DTPA-extractable Cd and Pb in soils reached up to 33% and 45%, and the water-soluble Cd and Pb decreased by 56% and 58%, respectively, when PHFP was added in soils at 4% dosage. In addition, the immobilization of Cd and Pb contributed to transforming water soluble, exchangeable and carbonate-bonded fractions to Fe and Mn oxides-bonded, organic-bonded and residual fractions. Under leaching with simulated acid rain, Cd and Pb release amount in PHFP amended soil declined by 53% and 52%, respectively, as compared with non-treated soil. The result implied that PHFP had a potential application for the remediation of Cd- and Pb-contaminated soils.

In this study, a novel model based on aromatic meta–substituent grouping was presented to predict the second–order rate constants (k) for OH oxidation of PCBs in gas–phase. Since the oxidation kinetics are dependent on the chlorination degree and position, we hypothesized that it may be more accurate for k value prediction if we group PCB congeners based on substitution positions (i.e., ortho (o), meta (m), and para (p)). To test this hypothesis, we examined the correlation of polarizability (α), a quantum chemical based descriptor for k values, with an empirical Hammett constant (σ+) on each substitution position. Our result shows that α is highly linearly correlated to ∑ σ o,m,p + based on aromatic meta–substituents leading to the grouping based predictive model. With the new model, the calculated k values exhibited an excellent agreement with experimental measurements, and greater predictive power than the quantum chemical based quantitative structure activity relationship (QSAR) model. Further, the relationship of α and ∑ σ o,m,p + for PCDDs congeners, together with highest occupied molecular orbital (HOMO) distribution, were used to validate the aromatic meta–substituent grouping method. This newly developed model features a combination of good predictability of quantum chemical based QSAR model and simplicity of Hammett relationship, showing a great potential for fast and computational tractable prediction of k values for gas–phase OH oxidation of polychlorinated compounds.

Here, the microbial responses to Cr(VI) and Pb(II) with bio-removal of the metals in water by Pannonibacter phragmitetus BB were explored. The comparative bacterial proteomics showed that the intracellular and extracellular Cr(VI) reduction proteins, Pb(II) adsorption by the lipoprotein and sugar-related bacterial proteins, as well as Pb(II) precipitation by phosphate and OH- were vital to the bio-removal of Cr(VI) and Pb(II). Moreover, the influx and efflux channels of Cr(VI) and Cr(III), Pb(II) transporters, extracellular siderophores for Pb(II) complexation and antioxidant proteins enabled the strain BB to resist the toxicity of Cr(VI) and Pb(II). In addition, the dynamic expression levels of the proteins related to reduction and transportation of Cr(VI), and adsorption, transportation and complexation of Pb(II) were dependent on the corresponding metal, respectively. The anti-oxidative stress system, such as superoxide dismutase, and Na+/H+ antiporters played central roles in the protein-protein interaction network to resist and detoxify Cr(VI) and Pb(II). The results of our study provide a novel insight for the physiological responses of the strain BB to the combined stresses of Pb(II) and Cr(VI).

DNA ligases are essential enzymes for DNA replication, repair, and recombination processes by catalyzing a nick-joining reaction in double-stranded DNA. The genome of the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 encodes a putative ATP-dependent DNA ligase (Tba ligase). Herein, we characterized the biochemical properties of the recombinant Tba ligase. The enzyme displays an optimal nick-joining activity at 65–70 °C and retains its DNA ligation activity even after heated at 100 °C for 2 h, suggesting the enzyme is a thermostable DNA ligase. The enzyme joins DNA over a wide pH spectrum ranging from 5.0–10.0, and its optimal pH is 6.0–9.0. Tba ligase activity is dependent on a divalent metal ion: Mn2+, Mg2+, or Ca2+ is an optimal ion for the enzyme activity. The enzyme activity is inhibited by NaCl with high concentrations. Tba ligase is ATP-dependent and can also use UTP as a weak cofactor; however, the enzyme with high concentrations could function without an additional nucleotide cofactor. Mass spectrometric result shows that the residue K250 of Tba ligase is AMPylated, suggesting that the enzyme is bound to AMP. The substitution of K250 of Tba ligase with Ala abolishes the enzyme activity. In addition, the mismatches at the first position 3′ to the nick suppress Tba ligase activity more than those at the first position 5′ to the nick. The enzyme also discriminates more effectively mismatches at 3′ to the nick than those at 5′ to the nick in a ligation cycling reaction, suggesting that the enzyme might have potential application in single nucleotide polymorphism.

Uracil DNA glycosylases (UDGs) play an important role in removing uracil from DNA to initiate DNA base excision repair. Here, we characterized biochemically a thermostable UDG from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 (Tba UDG), and probed its mechanism by mutational analysis. The recombinant Tba UDG cleaves exclusively uracil-containing ssDNA and dsDNA at 65°C. The enzyme displays an optimal cleavage activity at 70-75°C. Tba UDG cleaves DNA over a wide pH spectrum ranging from 4.0 to 11.0 with an optimal pH of 7.0-9.0. In addition, Tba UDG activity is independent on a divalent metal ion; however, both Zn2+ and Cu2+ completely inhibit the enzyme activity. Tba UDG activity is also inhibited by high NaCl concentration. Tba UDG removes uracil from DNA with the following preference: U≈U/G>U/T≈U/C>U/A. Kinetic results showed that Tba UDG cleaves uracil-containing ssDNA and dsDNA at a similar rate. The mutational studies showed that the E118A, N159A and H216A mutants completely abolish cleavage activity and retain compromised binding activity while the Y127A mutant displays similar cleavage and binding activities with the wild-type protein, suggesting that residues E118, N159 and H216 are essential for uracil removal and necessary for uracil recognition.

Dilute acid pretreatment liquor (DAPL) of lignocellulose contains abundant waste sugar resource for further upgrade. But the inhibitors, produced from sugar dehydrogenation, impedes the waste sugar valorization. In this study, an efficient biostrategy was developed to upgrade the waste sugar in DAPL. The concentration of sugar and phenolics in DAPL reached 19.61 g/L and 0.57 g/L, respectively, after pretreatment of rice straw with 0.5 % (v/v) sulfuric acid for 40 min at 121 °C. Bacillus megaterium B-10 could tolerate the furfural toxicity products in DAPL and convert the waste sugar into high-valuable products, polyhydroxyalkanoate (PHA). This polymer was characterized by GC–MS and 1H-NMR, and the as-synthesized PHA was identified as poly-3-hydroxybutyrate (PHB), a typical PHA. A demonstrated yield of PHB (1.496 g/L) was achieved, which accounted for 32.56 % of dry cell weight. Moreover, characterizations of PHB demonstrated that the biosynthetic PHB exhibited favorable thermoplastic properties. This bioconversion of B-10 provides an efficient strategy not only for waste pollution treatment, but also for lignocellulose valorization.

Here, the bio-nanocomposite (n-HFP + n-HFS)@An was developed to simultaneously immobilize Pb, Cd and As in the severely contaminated soil. The immobilization rates of diethylenetriaminepentaacetic acid (DTPA)/decarbonate-extracted bioavailable Pb, Cd and As were 59.87%, 31.28% and 62.30%, and the immobilization rates of their water-soluble forms were 63.12%, 60.02% and 89.39%, respectively. Moreover, the ten-year acid rain simulated leaching assay showed that the maximum cumulative release contents of Pb, Cd and As in the treated soil samples were decreased by 2.94, 2.46 and 40.60 times, comparing to the un-treated ones. Additionally, the results of SBRC (Solubility Bioaccessibility Research Consortium) revealed that the bioaccessible rates of the three metals in intestinal phase were lower than in gastric phase, and both of them decreased with increasing the immobilization time. The gastric bioaccessibility of Pb, Cd and As had a higher correlation with the contents of water-soluble forms, while the intestinal bioaccessibility was more strongly positively associated with the bioavailable forms.

The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%, respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combined with OH−, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) is fitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are 263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be applied to treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.

Serious arsenic (As)-contaminated soils have the potential to cause contamination of ground water and surface water, being toxic to plant, animals, and human. The aim of study was to characterize As contamination in the soils from Shimen realgar mine area, the largest realgar deposit in Asia. Total As concentrations, As chemical fractionation, and As potential solubility both at various land use types (smelting and processing plants (SPP), mining site (MS), and agriculture land (AL)) and soil depths (0–100 cm) were investigated. As speciation in soil was examined using X-ray absorption fine structure (XAFS) analysis, and risk assessment was also carried out to evaluate potential ecological risk of As contamination. As concentrations in the studied area were extremely high, and the total As concentration reached up to 5240.8 mg kg−1. Moreover, total As and NaHCO3-extractable As concentrations in all soil layers for various land use were far beyond the range of the non-contaminated soil. The potential ecological risk level of As posed higher to serious risk to the environment based on ecological risk index values. Sequential extraction confirmed that As is mostly bonded with amorphous and poorly crystalline hydrous iron and aluminum oxides (65 ∼ 70 %), and only a small proportion (about 11 %) is partitioned in residual fraction, suggesting high risk of As mobilization. According to XAFS analysis, As was predominantly present in the form of arsenate, and arsenite was also found in the samples from SPP, MS, and AL. The results indicate that the extra high concentrations of As were caused by both natural geochemical enrichment and long-lasting ore mining, smelting, and processing, and land use can greatly influence As contents in surface soil. These findings can be important for risk assessment and for the development and implementation of suitable management and remediation strategies.

Ramie (Boehmeria nivea L.) is the oldest cash fiber crop in China and is widely grown in antimony (Sb) mining areas. To evaluate the extent of Sb resistance and tolerance, the growth, tolerance index (TI), Sb content in plant parts and in Hoagland solution, bioaccumulation factor (BF), photosynthesis, and physiological changes in Sb-contaminated B. nivea (20, 40, 80, and 200 mg L−1 Sb) grown hydroponically were investigated. The Sb tolerance and resistance of ramie were clearly revealed by growth inhibition, a TI between 13 and 99 %, non-significant changes in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (photosystem II (PSII)) and single-photon avalanche diode (SPAD) value, a significant increase in Sb in plant parts, BF >1, and an increase in catalase (CAT) and malondialdehyde (MDA) at 200 mg L−1 Sb. Under increasing Sb stress, nearly the same non-significant decline in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (PSII), relative quantum yield of photosystem II (φPSII), and photochemical quenching (qP), except for F v /F m at 20 mg L−1 Sb, were recorded. SPAD values for chlorophyll under Sb stress showed an increasing trend, except for a slight decrease, i.e.

A novel modified method of hollow tubular alumina was investigated for improving the ability to remove fluoride. In this paper, we designed two parts to improve the adsorption capacity of fluoride: (1) increased the exposed surface area by compounding hollow tubular structure; (2) hydroxylated with different concentrations of H2O2 from 0 to 10 wt%. The modified alumina had uniform hollow tubular and crystal form of γ-Al2O3. Modified hollow tubular alumina exhibited a good performance of 74.25% with 1% H2O2. The kinetic and thermodynamic were thoroughly explained to fit different models. It demonstrated that the pseudo-second-order model and Freundlich model, indicating that chemical and heterogeneous adsorption. The adsorptive velocities of 1% H2O2/Al2O3 were 8.07 × 10−8 and 1.39 × 10−6 m/s when the initial concentrations were 10 ppm and 100 ppm, respectively. The adsorption mechanism was discussed and the adsorbent was stable after adsorbing fluoride. The addition of hydrogen peroxide promoted the more hydroxyl groups, and the exchange hydroxyl groups with fluoride were the main mechanism of adsorption. The ratio of hydroxyl groups with the form of Al–O–OH and Al–OH descended from 80%, 29.3%–30.4%, 20.1%, respectively. These results show hollow structure and modified with H2O2 are the economic and environmental methods for enhancing to remove fluoride.

The effect of ageing solutions on the aroma profile of fermented soybean curds (furu) was studied. Furu aged with ethanol or rapeseed oil ageing solutions (EAS or RAS, respectively) were prepared. More varieties and higher contents of esters were found in EAS-furu; and higher contents of benzaldehyde, phenylacetaldehyde, palmitic acid and octanoic acid (products of the catabolism of phenylalanine and fatty acids) were found in RAS-furu, while its contents of total aroma compounds were lower. In addition, beany flavor compounds in furu could not be detected after ageing, and aroma compounds obtained from different ageing solutions and seasoning increased with fermentation time. All these results indicated that EAS and RAS made different contributions to the aroma profile of furu, and the potential combinations of the two ageing solutions might be interesting to explore in future studies.

To develop an efficient, convenient and cost-effective method to simultaneously remove pollution of As(III), Cd(II) and Pb(II) in wastewater, a strategy to fabricate hybrid bio-nanocomposites ((n-HFP + n-HFS)@An) of nano hydroxy ferric phosphate (n-HFP) and hydroxy ferric sulfate (n-HFS) particles coating on Aspergillus niger was applied. The scanning electron microscope and energy dispersive spectrum analyses showed that (n-HFP + n-HFS)@An composites had been successfully developed which well solved the self-agglomeration problem of the nano particles. Comparing to the bulk nanoparticles, the adsorption rates of the (n-HFP + n-HFS)@An composites for the three metals were promoted 145.34, 28.98 and 25.18% and reached 76.84, 73.62 and 94.31%, respectively. Similarly, the adsorption capacities for As(III), Cd(II), and Pb(II) were 162.00, 205.83 and 730.79 mg/g, respectively. Moreover, the pseudo-second-order kinetic model was more relevant to the adsorption on the three metals by (n-HFP + n-HFS)@An, and adsorbing As(III) was fitted to the Freundlich isotherm model, while the adsorption on Cd(II) or Pb(II) was related to the Langmuir isotherm model. In addition, the adsorption of Cd(II) and Pb(II) was associated with transformation of hydroxyl groups and precipitation with phosphate. As(III) was adsorbed through exchange between AsO2− and SO42− in the (n-HFP + n-HFS)@An composites.

The release of hexavalent chromium [Cr(VI)] into water bodies poses a major threat to the environment and human health. However, studies of the biological response to Cr(VI) are limited. In this study, a toxic bacterial mechanism of Cr(VI) was investigated using Pannonibacter phragmitetus BB (hereafter BB), which was isolated from chromate slag. The maximum Cr(VI) concentrations with respect to the resistance and reduction by BB are 4000 mg L−1 and 2500 mg L−1, respectively. In the BB genome, more genes responsible for Cr(VI) resistance and reduction are observed compared with other P. phragmitetus strains. A total of 361 proteins were upregulated to respond to Cr(VI) exposure, including enzymes for Cr(VI) uptake, intracellular reduction, ROS detoxification, DNA repair, and Cr(VI) efflux and proteins associated with novel mechanisms involving extracellular reduction mediated by electron transfer, quorum sensing, and chemotaxis. Based on metabolomic analysis, 174 metabolites were identified. Most of the upregulated metabolites are involved in amino acid, glucose, lipid, and energy metabolisms. The results show that Cr(VI) induces metabolite production, while metabolites promote Cr(VI) reduction. Overall, multi-enzyme expression and metabolite production by BB contribute to its high ability to resist/reduce Cr(VI). This study provides details supporting the theory of Cr(VI) reduction and a theoretical basis for the efficient bioremoval of Cr(VI) from the environment.

International audience; Endonuclease V (Endo V) is an important enzyme for repairing deoxyinosine in DNA. While bacterial and eukaryotic endo Vs have been well studied, knowledge of archaeal endo Vs is limited. Here, we first presented biochemical characterization of a thermostable endonuclease V from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 (Tba endo V). The recombinant enzyme possessed optimal endonuclease activity for cleaving deoxyinosine-containing DNA at 70–90 °C. Furthermore, Tba endo V can withstand 100 °C for 120 min without significant loss of its activity, suggesting the enzyme is thermostable. Tba endo V exhibited varying cleavage efficiencies at various pH levels from 6.0 to 11.0, among which an optimal pH for the enzyme was 8.0–9.0. In addition, a divalent metal ion was required for the enzyme to cleave DNA. Mn2+ and Mg2+ were optimal ions for the enzyme's activity whereas Ca2+, Zn2+ and Co2+ inhibited the enzyme activity. Moreover, the enzyme activity was suppressed by high NaCl concentration. Tba endo V bound to all DNA substrates; however, the enzyme exhibited a higher affinity for binding to deoxyinosine-containing DNA than normal DNA. Our work provides valuable information for revealing the role of Tba endo V in the base excision repair pathway for deoxyinosine repair in Thermococcus.

Combining bioleaching by the gross biosurfactants of Burkholderia sp. Z-90 and flocculation by poly aluminium chloride (PAC) was proposed to develop a potential environment-friendly and cost-effective technique to remediate the severely contaminated soils by heavy metals. The factors affecting soil bioleaching by the gross biosurfactants of Burkholderia sp. Z-90 were optimized. The results showed the optimal removing efficiencies of Zn, Pb, Mn, Cd, Cu, and As by the Burkholderia sp. Z-90 leachate were 44.0, 32.5, 52.2, 37.7, 24.1 and 31.6%, respectively at soil liquid ratio of 1:20 (w/v) for 5 d, which were more efficient than that by 0.1% of rhamnolipid. The amounts of the bioleached heavy metals by the Burkholderia sp. Z-90 leachate were higher than that by other biosurfactants in the previous studies, although the removal efficiencies of the metals by the leachate were relatively lower. It was suggested that more heavy metals caused more competitive to chelate with function groups of the gross biosurfactants and the metal removal efficiencies by biosurfactants in natural soils were lower than in the artificially contaminated soils. Moreover, the Burkholderia sp. Z-90 leachate facilitated the metals to be transformed to the easily migrating speciation fractions. Additional, the results showed that PAC was efficient in the following flocculation to remove heavy metals in the waste bio-leachates. Our study will provide support for developing a bioleaching technique model to remediate the soils extremely contaminated by heavy metals.

Fe–Mn binary oxide flower-like three-dimensional nanostructure synthesized from a hydrothermal procedure was used to remove arsenic (As) from aqueous solution. The samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR). SEM images revealed that the Fe–Mn binary oxide was dispersed as flower-like spheres with a diameter of 500 − 800 nm and the width of the petals was 20 − 30 nm. Sorption of the As to the Fe–Mn binary oxide reached equilibrium in less than 180 s, which is much faster than pure MnO2 and amorphous iron manganese binary oxide. The adsorption isotherm agreed well with the Freundlich adsorption model with adsorption capacities of 26.5 mg/g, when the equilibrium concentration was 34.5 mg/L. The effect of temperature revealed that the adsorption of As was exothermic, and the adsorption decreased with increasing temperature from 20 °C to 70 °C. The removal percentage of As by Fe–Mn binary oxide reached 100% from aqueous solution at pH 4.0 − 6.0. The Fe–Mn binary oxide nano-flowers are a potential highly efficient nanomaterial for removal of As from water.

Methylsiloxane and fluorinated segments were introduced into the polymer backbone of polyurethane by direct reaction of isocyanate with dialcohol terminated perfluoropolyether (E10-H) and poly(dimethyl siloxane) (PDMS). The polyurethane structure was revealed by Fourier transform infrared spectrometer in ATR mode and Xray photoelectron spectroscope. It was found that the silicon and fluorine moieties easily migrated to the surface of material in film-forming process due to their lower energy, so the water contact angle on membrane surface was greatly enhanced (maximum 100.1°), and the hydrophobic property of material was improved. Different degree of phase separation was observed by scanning electron microscope. Increment of PDMS or E10-H content caused the phase separation obviously, but section of PDMS and E10-H modified polyurethane showed that phase separation reduced. The linear dynamic viscoelastic measurements indicated that the dynamic storage modulus of all samples increased with the increment of frequency, and PDMS modified WPU’s grew fastest. The slope of G′ vs. G″ showed a decrement, so each sample had a shear thinning behavior. The perfluoropolyether oil was to reduce viscosity of the system.

Culture-independent and -dependent methods were used to evaluate the genetic diversity of hexavalent chromium-resistant bacteria in contaminated soils. Denaturing gradient gel electrophoresis (DGGE) showed that hexavalent chromium-resistant bacteria in contaminated soils had significant structural diversity that was not related to the concentration of hexavalent chromium, while the diversity of soil bacterial communities was correlated with soil pH. Twenty-two chromium-resistant bacterial strains were isolated from contaminated soil, including members of Brevundimonas, Micrococcus, Exiguobacterium, Alcaligenes and Pannonibacter. Repetitive sequence-based polymerase chain reaction showed that the BOX- primer produced the more complex banding patterns than the ERIC- and REP- primers, indicating a high degree of genotypic diversity. These bacterial strains varied in ability to reduce hexavalent chromium. Pannonibacter reduced 300 mg·L−1 of hexavalent chromium in solution within 24 h. X-ray photoelect...

A low crystalline Fe-oxyhydroxy sulfate (FeOS) was used to immobilize arsenic (As) in soils in this study. The effects of FeOS amount, treatment time and soil moisture on As immobilization were investigated. The results showed that water-soluble and NaHCO3-extractable As were immobilized by 53.4-99.8 and 13.8-73.3% respectively, with 1-10% of FeOS addition. The highest immobilization of water-soluble (98.5%) and NaHCO3-extractable arsenic (47.2%) was achieved under condition of 4% of FeOS and 80% of soil moisture. Further, more amounts of FeOS addition resulted in less time requirement for As immobilization. Sequential chemical extraction experiment revealed that easily mobile arsenic phase was transferred to less mobile phase. The FeOS-bonded As may play a significant role in arsenic immobilization. Under leaching with simulated acid rain at 60 times pore volumes, accumulation amount of As release from untreated soil and soil amended with FeOS were 98.4 and 1.2 mg, respectively, which correspond to 7.69 and 0.09% of total As amounts in soil. The result showed that the low crystalline FeOS can be used as a suitable additive for arsenic immobilization in soils.

The present study aimed to investigate the therapeutic effects of Euterpe oleracea Mart. (EO) on alcoholic liver diseases (ALD). A total of 30 Wistar rats were randomly divided into three groups (10 rats per group), including alcohol group (alcohol intake), EO group (alcohol + EO puree intake) and control group (distilled water intake). The activity of superoxide dismutase (SOD) and alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the levels of cholesterol (CHO), triglyceride (TG), malondialdehyde (MDA) and glutathione (GSH) in the serum as well as the liver tissue levels of interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) were measured. Histopathological changes in liver tissues were observed by hematoxylin and eosin staining. Reverse-transcription quantitative PCR analysis was performed for detecting the expression of nuclear factor (NF)-κB and CD68. The results indicated that EO intake significantly decreased ALT, AST, ALP, TG and CHO as well as the hepatic index in alcohol-treated rats. In addition, EO treatment relieved alcohol-induced oxidative stress by decreasing the levels of MDA and TG, and increasing the activity of SOD and GSH levels. In addition, the expression of TNF-α, TGF-β, IL-8, NF-κB and CD-68 in the liver were decreased by EO treatment. Furthermore, EO intake alleviated the histopathological liver damage, including severe steatosis and abundant infiltrated inflammatory cells. In conclusion, EO alleviated alcohol-induced liver injury in rats by alleviating oxidative stress and inflammatory response.

Hydroxyl radical (•OH) and sulfate radical anion (SO4•-) based advanced oxidation technologies (AOTs) are effective methods to treat trace organic contaminants (TrOCs) in engineered waters. Although both technologies result in the same overall removal of TrOCs, the mechanistic differences between these two radicals involved in the oxidation of TrOCs remain unclear. In this study, we experimentally examined the degradation kinetics of neutral ibuprofen (IBU), a representative TrOC, by •OH and SO4•- at pH3 in UV/H2O2 and UV/persulfate systems, respectively. The second-order rate constants (k) of IBU with •OH and SO4•- were determined to be 3.43±0.06×109 and 1.66±0.12×109M-1s-1, respectively. We also theoretically calculated the thermodynamic and kinetic behaviors for reactions of IBU with •OH and SO4•- using the density functional theory (DFT) M06-2X method with 6-311++G** basis set. The results revealed that H-atom abstraction is the most favorable pathway for both •OH and SO4•-, but due to the steric hindrance SO4•- exhibits significantly higher energy barriers than •OH. The theoretical calculations corroborate our experimental observation that SO4•- has a smaller k value than •OH in reacting with IBU. These comparative results are of fundamental and practical importance in understanding the electrophilic interactions between radicals and IBU molecules, and to help select preferred radical oxidation processes for optimal TrOCs removal in engineered waters.

In order to improve the efficiency of bioleaching heavy metal from the contaminated soil using Penicillium chrysogenum (P. chrysogenum), experiment was conducted to evaluate the influence of heavy metal stress on P. chrysogenum during bioleaching. The morphology and physiology of P. chrysogenum were observed. Assuming that the heavy metals are all leached out from the experiment soil, heavy metals are added into the agar medium by simulating the heavy metal content in the soil. It is concluded that the survivable heavy metal contaminated soil mass range for P. chrysogenum is 2.5–5.0 g. As for biomass determination, the contaminated soil is added into the liquid medium directly. The soil mass that P. chrysogenum can be survivable is in the range of 2.5–8.75 g. In this mass range, the biomass of P. chrysogenum is bigger than that of the control sample. 10 g soil mass is the threshold of the growth of P. chrysogenum. 102.2 mg/L gluconic acid, 156.4 mg/L oxalic acid, 191.6 mg/L pyruvic acid, 0.02 mg/L citric acid, 0.03 mg/L malic acid and 70.6 mg/L succinic acid are determined after 15 d bioleaching. The mycelium is broken into fragments, and heavy metals are adsorbed on the cell wall or transported into the cytoplasm during bioleaching. The GOD activity declines from 1.08 U/mL to 0.2 U/mL under 400 mg/L of multi-metal stress. The influence of Pb on GOD activity is bigger than that of Cr and Cd, and the GOD activity is not influenced apparently by Mn, Zn and Cu.