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Bi-based materials are promising catalysts for electrochemical reduction of carbon dioxide (CO2) to formate, but remain challenging in terms of activity and stability. Herein, we report the facile synthesis of Zn-doped Bi nanosheets (Zn–Bi NSs) as a highly active and robust catalyst for electrochemical reduction of CO2 to formate. Specifically, the Zn–Bi NS catalyst can be obtained using a hydrothermal method to prepare a Zn-decorated Bi2O2CO3 nanosheet followed by electrochemical reduction treatment. The as-prepared catalyst exhibits a remarkable formate faradaic efficiency of 94.6% and a high formate current density of 40.5 mA cm−2 at −1.2 V vs. reversible hydrogen electrode (RHE). In particular, the faradaic efficiency of formate remained at above 90% over a wide potential window from −0.8 to −1.2 V vs. RHE. In the H-type electrolytic cell, the Zn–Bi NS catalyst can be operated stably for 10 h at a cathode potential of −1.0 V vs. RHE with good retention of the physical phase. [ABSTRACT FROM AUTHOR]

Subduction-related magmatism is a significant contributor to arc building and continental growth. In the active convergent margin of the SW Japan arc, voluminous volcanic rocks and mafic dykes formed through subduction and back-arc rifting during Miocene. In this study, we investigate a suite of felsic volcanic rocks (rhyolite and dacite) and lamprophyres from central Shikoku Island, which occur in the north-central part of the Chichibu belt and Sanbagawa belt in the Outer zone of the SW Japan arc. Whole-rock geochemistry results show that the rhyolite and dacite samples are peraluminous, belong to the high-K calc-alkaline series, show LREE and LILE enrichment, HREE and HFSE depletion that suggest arc volcanic affinity. The lamprophyre samples belong to alkali lamprophyre, show LREE and HFSE enrichments, and display OIB (oceanic island basalt)-like geochemical features. The 206Pb/238U weighted mean ages of the zircons from the rhyolite and dacite samples range from 14.39 ± 0.21 Ma to 13.92 ± 0.30 Ma, whereas the lamprophyre shows 206Pb/238U weighted mean age of 12.21 ± 0.35 Ma. Zircon Lu-Hf isotope data suggest that the rhyolite and dacite were derived from the remelting of the arc crustal rocks and that the lamprophyre was derived from depleted mantle sources and was contaminated by crustal materials. The felsic volcanic rocks (rhyolite and dacite) can be correlated to Miocene (15.5 Ma to 13.5 Ma) magmatism in the Outer Zone of the SW Japan arc. The formation of lamprophyre dykes in the SW Japan arc may be related to the subhorizontal mantle flows beneath the SW Japan arc associated with the opening of the Japan Sea back-arc basin or asthenosphere upwelling through the slab-tear of the Philippine Sea Plate beneath the SW Japan arc. Our study shows that the SW Japan Arc was built by multiple magmatism from diverse sources in an active convergent margin. [ABSTRACT FROM AUTHOR]

1,2-Dicarbofunctionalization of alkenes represents an appealing strategy for chemical bond formation in organic synthesis, which could enable the rapid construction of molecular complexity from simple and readily available starting materials by incorporating two functional groups onto a carbon–carbon double bond in one step. In this field, the dicarbofunctionalization of alkenes with different alkyl radicals in a controlled manner represents an elegant and versatile strategy to access structurally diverse functionalized alkanes, which have witnessed significant progress over the last five years. Due to the importance of alkyl radicals in organic synthesis and medicinal chemistry, this review provides a comprehensive perspective on the development of alkyl radical precursors including electrophilic precursors such as alkyl halides, alkyl peroxides, alkyl NHP esters, cycloketone oxime esters, and Katritzky pyridinium salts, and nucleophilic precursors such as alkyl acids, alkyl oxalates, alkylborates, alkylsilicates, and unactivated hydrocarbons, which generate alkyl radicals by photocatalysis or transition metal catalysis to engage in dicarbofunctionalization under oxidative reaction conditions, redox-neutral conditions, or reductive conditions. The mechanisms of these dicarbofunctionalization reactions have also been discussed in detail. [ABSTRACT FROM AUTHOR]

A mild copper-catalyzed alkylarylation of vinylarenes with cycloalkylsilyl peroxides and boronic acids is described. This three-component protocol provides a straightforward approach to the remote keto-functionalized 1,1-diarylmethane derivatives. A radical pathway initiated by C–C bond cleavage is proposed for this tandem reaction. [ABSTRACT FROM AUTHOR]

Nitrogen‐rich compounds involving the cyclo‐pentazole anion (cyclo‐N5−) have attracted extensive attention due to higher energy release and environmental friendliness than traditional high energy density materials (HEDMs). However, the synthesis of stable HEDMs with cyclo‐N5− is still a challenge. In this study, the effect of nine solvents on the geometrical and electronic structures and solvation energies of Zn(N5)2, one of the recently synthesized nitrogen‐rich compounds, was studied using the density functional theory and the polarized continuum model. The results indicated an increase in the stability of Zn(N5)2 in the solution phase compared to the vacuum phase, and the stability of Zn(N5)2 increases with increasing dielectric constants. The energy gap of frontier molecular orbitals and the absolute value of total energy in water are the largest, revealing that Zn(N5)2 is more stable in water than in other solvents. To understand the stabilization mechanism of Zn(N5)2 by water, further studies were performed with the natural bond orbital (NBO) analysis and the quantum theory of atoms in molecules (QTAIM) analysis using the explicit solvent model. The charge transfer and the hydrogen bonds are observed between Zn(N5)2 and water, which are beneficial to improvement of the stability of Zn(N5)2. This may indicate the solvents that have strong interactions with the cyclo‐N5− candidate may improve the possibility of success of synthesis. [ABSTRACT FROM AUTHOR]

Ocean island basalts (OIBs) and associated sedimentary units form part of the ocean plate stratigraphy accreted onto island arcs or continental arcs and provide important insights into convergent margin processes. Here, we investigate some of the typical localities of Sanpozan, Shirakidani, and Kamiananai within the Chichibu composite belt in Kochi, SW Japan, where the accretionary complexes incorporate OIBs and sedimentary rocks that preserve the travelogue of an oceanic plate from a mid‐oceanic ridge (MOR) to subduction zone. We present petrology and geochemistry, as well as zircon U–Pb geochronology and REE data of the accreted OIB and sedimentary formations from Sanpozan, Shirakidani, and Kamiananai. The OIBs are enriched in LILE and LREE and depleted in HREE. The chondrite‐normalised REE patterns of zircon grains from OIBs and sedimentary rocks display LREE depletion and HREE enrichment, sharply positive Ce and Sm anomalies and negative Pr and Eu. LA‐ICP‐MS U–Pb geochronology of zircon grains from the OIBs shows three major populations with 206Pb/238U mean ages of 164–456, 724–955, and 1,638–2,202 Ma. The diverse ages suggest heterogeneous recycled source components in the plume‐related upwellings that generated the OIBs, as well as different times of formation and accretion of the Palaeozoic and Mesozoic oceanic islands. The dominant population of zircon grains from the sedimentary units shows 206Pb/238U mean ages of 147 and 288 Ma and indicate a major change in the provenance regime with subduction and the disappearance of older arcs attesting to the destruction of continental crust in convergent margins. [ABSTRACT FROM AUTHOR]

In the environment, persistent free radicals (PFR) have adverse effects on human health. PFR are generated by thermal conversion of biomass, such as hydrothermal carbonization to produce hydrochar. So far, the mechanism and control factors of PFR production in hydrochar are poorly known. Therefore, we investigated here the impacts of hydrothermal temperature, residence time and solid load on the formation of PFR in hydrochar from hydrothermal carbonization of rice straw, by electron paramagnetic resonance (EPR) coupled with Fourier transform infrared spectrometers. Results show that the EPR signal intensity increased with increasing hydrothermal temperature from 180 to 240 °C and then decreased at 260 °C. A shorter residence time and a higher solid load led to formation of more PFR in hydrochar. The types of PFR also depended on hydrothermal temperature, residence time and solid load. This is the first report on the formation of PFR and relevant influencing factors during hydrothermal conversion of biomass. Based on these results, hydrochar from hydrothermal conversion of biomass at relatively higher temperature, i.e., 260 °C, longer residence time, i.e., 4 h, and lower solid load, i.e., 1:10, is suggested for safer application. [ABSTRACT FROM AUTHOR]

Wastewater treatment systems are considered as hotspots for release of antibiotic resistance genes (ARGs) into the environment. Anaerobic-aerobic sequential (AAS) bioreactors now are intensively used for wastewater treatment worldwide. However, the occurrence of ARGs in wastewater treatment systems exposed to low-level (i.e., sub-inhibitory) antibiotic is poorly known. Here, we studied the distribution patterns of seven tetracycline resistance genes ( tet genes) including tet (A), tet (C), tet (G), tet (X), tet (M), tet (O), and tet (W), as well as one mobile element [class 1 integron ( intI1 )] in AAS bioreactors under exposure to tetracycline from 50 μg/L to 500 μg/L. Additionally, effect on the removal performance of nutrients and tetracycline in both anaerobic and aerobic units was also investigated. A tetracycline concentration gradient selected for bacterial resistance in the anaerobic reactor, with the exception of tet (A) and tet (W), and the tetracycline removal deteriorated by 47%. However, the abundance of tet and intI1 genes reduced in the subsequent aerobic unit, and the removal of tetracycline, soluble COD, and NH 4 + -N maintained at average efficiencies of 91%, 90%, and 93%, respectively. The level of tet (X) was largely unaffected by AAS treatment. It is notable that intI1 genes probably played a crucial role on the horizontal dissemination of tet genes. The tetracycline levels and intI1 genes appear to be the primary factors influencing the occurrence of tet genes in AAS bioreactors. Nonetheless, AAS treatments still show promise for reducing antibiotics, ARGs and mobile elements without affecting nutrient removal, and need further research for practical applications. [ABSTRACT FROM AUTHOR]

Abstract: An iron‐catalyzed radical allylation of cyclobutanone oxime esters with allylic sulfones via C−C bond cleavage is reported. This protocol provides a straight‐forward approach to cyanoalkylated alkenes with good functional group tolerance and high regioselectivity. Furthermore, this reaction can be further expanded to ring‐opening of less‐strained cyclopentanone oxime esters, leading to desired cyanoalkylated alkenes in good yields. [ABSTRACT FROM AUTHOR]

Background: Postoperative endocrine therapy is known to reduce recurrence and mortality in patients with estrogen receptor (ER)- or progestogen receptor (PR)-positive breast cancer. Correlates and determinants of compliance with endocrine therapy among Chinese patients with breast cancer are not known. The aim of this study was to elucidate the efficacy and adherence of endocrine therapy in China and suggest effective improvements on the adherence. Patients and methods: We analyzed the survival of 1,110 patients eligible for endocrine therapy and adherence of 699 patients to endocrine therapy. Kaplan��Meier curves, log-rank tests and Cox proportional hazard models were used to evaluate survival, and logistic regression models were used to assess variables associated with treatment adherence. Results: Long-term endocrine therapy was associated with lower recurrence rate (HR 0.72; 95% CI 0.56��0.93; p=0.013). Adherence to endocrine therapy was only 63.1%. Sociodemographic characteristics of patients, clinical- and medication-related characteristics and patients�� attitudes were associated with adherence to endocrine therapy. Conclusion: Adherence to endocrine therapy in Chinese patients with ER+/PR+ breast cancer was ,65%. Both patients and physicians should take progressive steps to improve the rate of adherence. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed cycloisomerisation reaction of 1,6-enyne acetic esters have been developed. This cyclization reaction shows excellent regioselectivity and good functional group tolerance to obtain five-membered nitrogenated heterocyclic conjugated trienes in moderate to excellent yields. The resulting conjugated trienes could be facilely converted to highly substituted benzenes through Diels-Alder reactions. [ABSTRACT FROM AUTHOR]

Many distributed graph processing frameworks have emerged for helping doing large scale data analysis for many applications including social network and data mining. The existing frameworks usually focus on the system scalability without consideration of local computing performance. We have observed two locality issues which greatly influence the local computing performance in existing systems. One is the locality of the data associated with each vertex/edge. The data are often considered as a logical undividable unit and put into continuous memory. However, it is quite common that for some computing steps, only some portions of data (called as some properties) are needed. The current data layout incurs large amount of interleaved memory access. The other issue is their execution engine applies computation at a granularity of vertex. Making optimization for the locality of source vertex of each edge will often hurt the locality of target vertex or vice versa. We have built a distributed graph processing framework called Photon to address the above issues. Photon employs Property View to store the same type of property for all vertices and edges together. This will improve the locality while doing computation with a portion of properties. Photon also employs an edge-centric execution engine with Hilbert-Order that improve the locality during computation. We have evaluated Photon with five graph applications using five real-world graphs and compared it with four existing systems. The results show that Property View and edge-centric execution design improve graph processing by 2.4X. [ABSTRACT FROM AUTHOR]

Activated sludge has been identified as a potential significant source of antibiotic resistance genes (ARGs) to the environment. Anaerobic digestion is extensively used for sludge stabilization and resource recovery, and represents a crucial process for controlling the dissemination of ARGs prior to land application of digested sludge. The objective of this study is to investigate the effect of zero valent iron (Fe 0 ) on the attenuation of seven representative tetracycline resistance genes ( tet , tet (A), tet (C), tet (G), tet (M), tet (O), tet (W), and tet (X)), and the integrase gene intI1 during thermophilic anaerobic co-digestion of waste sludge and kitchen waste. Significant decrease ( P < 0.05) in the quantities of tet (except tet (W)) and intI1 genes was observed at Fe 0 dosage of 5 g/L, whereas no significant differences ( P > 0.05) were found for all gene targets between digesters with Fe 0 dosages of 5 and 60 g/L. A first-order kinetic model favorably described the trends in concentrations of tet and intI1 gene targets during thermophilic anaerobic digestion with or without Fe 0 . Notably, tet genes encoding different resistance mechanisms behaved distinctly in anaerobic digesters, although addition of Fe 0 could enhance their reduction. The overall results of this research suggest that thermophilic anaerobic digestion with Fe 0 can be a potential alternative technology for the attenuation of tet and intI1 genes in waste sludge. [ABSTRACT FROM AUTHOR]

Activated sludge system is an important process of domestic and industrial wastewater treatment containing highly diverse microbial communities. In this study, high-throughput sequencing was applied to examine the microbial community composition and diversity of activated sludge samples from four full-scale municipal wastewater treatment plants (WWTPs) in Shanghai. A relationship between microbial communities and environmental variables was examined. Proteobacteria was the most dominant phylogenetic group, followed by Bacteroidetes and Firmicutes. A total of 166 genera were commonly shared by all seven sludge samples, including Zoogloea, Dechloromonas, Thauera, Nitrospira, Arcobacter, etc. Besides these shared populations, certain unique bacterial populations were found abundant in individual sludge sample. Canonical correspondence analysis (CCA) indicated that influent COD and pH had the greatest influence on microbial community compositions, whereas dissolved oxygen (DO) exhibited the least influence. The operating process was likely to foster diversity of the microbial communities inhabiting the wastewater treatment facilities. Alternative operation methods including a fluctuation of anoxic, oxic, and anaerobic conditions were favorable for promoting the growth of diverse microbial populations in activated sludge systems. [ABSTRACT FROM AUTHOR]

HTC (hydrothermal carbonization) is a technically-attractive thermal conversion process for biomass to produce solid carbonaceous products at mild conditions. EB (eucalyptus bark) was used as a feedstock for producing hydrochar by HTC. Effect of process conditions on the yield and physicochemical properties of hydrochar was examined by varying carbonization temperature over the range of 220–300 °C and varying residence time over the range of 2–10 h. With increase in temperature, the hydrochar yield decreased slightly from 46.4% at 220 °C to 40.0% at 300 °C. The O/C and H/C atomic ratios reduced from 1.69 and 0.80 to 0.83 and 0.23, respectively, which was mostly related to dehydration, decarboxylation and demethanation reactions. The oxygen containing functional groups decreased with increasing temperature. HHV (higher heating value) of hydrochar was in the range of 20.2–29.2 MJ/kg. Thermogravimetric analysis showed that hydrochar products obtained at temperature over 220 °C exhibited almost the same thermal behaviors. In comparison, the influence of residence time on the yield, physicochemical properties and thermal behavior of hydrochar was marginal. [ABSTRACT FROM AUTHOR]

In the last few years, the development of versatile methodologies to incorporate trifluoromethyl groups into organic molecules has attracted significant attention in synthetic chemistry. This review gives an overview over the development on the trifluoromethylation of alkynes, which have not been solely discussed before. Formation of diverse C(sp, sp2, sp3)CF3 bonds are all covered in this review. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is a global challenge and represents a growing threat on human health worldwide. Wastewater treatment plants (WWTPs) are generally considered as hotspots for control and/or dissemination of antibiotic resistance. The role of antibiotics, antibacterial residues, and heavy metals played on the evolution and spread of antibiotic resistance is still not well understood. Here, the occurrence of antibiotics (i.e., macrolides, tetracyclines, sulfonamides, and quinolones), antibacterial residues (i.e., triclosan), as well as heavy metals (i.e., cadmium, chromium, copper, zinc, lead, and nickel) in urban wastewater was investigated. Also, the abundances of erythromycin resistance genes (ERY-ARGs) including ere(A), ere(B), mef(A)/ mef(E), erm(A), erm(B), erm(C), and msr(A)/ msr(B) genes were screened. A relationship between certain antibiotics, antibacterial residues, and heavy metals and ERY-ARGs was demonstrated. ERY presented significant correlations (0.883 < r < 0.929, P < 0.05) with ere(A), ere(B), and mef(A)/ mef(E) genes, while tetracycline exhibited a significant correlation ( r = 0.829, P < 0.05) with erm(B) genes. It is noteworthy that triclosan correlated significantly (0.859 < r < 0.956, P < 0.05) with ere(A), ere(B), mef(A)/ mef(E), and erm(B) genes. In addition, significantly positive correlations (0.823 < r < 0.871, P < 0.05) were observed between zinc and lead and certain ERY-ARGs (i.e., ere(B), mef(A)/ mef(E), erm(B), etc.). Further investigations should be involved to elucidate the co-selection and/or cross-selection mechanisms due to co-existence of these selective factors in urban wastewater. [ABSTRACT FROM AUTHOR]

A novel and convenient metal-free nitration and cyclization of 1,6-enynes has been developed. Two C–C bonds and one C–N bond were constructed in one process in this reaction. This transformation is proven to have relatively good functional-group applicability and can be scaled up to gram quantities in satisfactory yields. According to the following experimental facts and related literature reports, a radical pathway was involved in this transformation. [ABSTRACT FROM AUTHOR]

Apolipoproteins, synthesized mainly in liver and intestine and bounded to lipids, play important roles in lipid transport and uptake through the circulation system. In this study, an apolipoprotein A-I gene homologue was cloned from orange-spotted grouper Epinephelus coioides (designed as Ec-ApoA-I) by rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of Ec-ApoA-I was comprised of 1278 bp with a 792 bp open reading frame (ORF) that encodes a putative protein of 264 amino acids. Quantitative real-time PCR (qPCR) analysis revealed that Ec-ApoA-I was abundant in liver and intestine, and the expression in liver was significantly ( P < 0.01) up-regulated after the stimulation of LPS, Poly(I:C), Vibrio alginolyticus , and Singapore grouper iridovirus (SGIV). Recombinant Ec-ApoA-I (rEc-ApoA-I) was produced in Escherichia coli BL21 (DE3) expression system exhibited bacteriolyticactivity against Microcococcus lysodeikticus and Aeromonas hydrophila . Intracellular localization revealed that Ec-ApoA-I distributed in both cytoplasm and nucleus, and predominantly in the cytoplasm. Overexpression of Ec-ApoA-I in grouper Brain (GB) cells could inhibit the replication of SGIV. These results together indicated that Ec-ApoA-I perhaps is involved in the responses to bacterial and viral challenge. [ABSTRACT FROM AUTHOR]

An efficient approach for Cu-catalyzed thiolation of C sp2 –H bonds of directing-group-containing aromatic amides with 1°, 2°, and 3° aliphatic thiols and thiophenols has been developed. This method shows excellent functional group tolerance and provides a straightforward way for the preparation of aryl thioethers. [ABSTRACT FROM AUTHOR]

A novel copper-catalyzed one-pot functionalization of homopropargylic alcohols that involves trifluoromethylation, aryl migration, and formation of a carbonyl moiety has been developed. This reaction constitutes the first direct conversion of homopropargylic alcohols into CF3-containing 3-butenal or 3-buten-1-one derivatives in a regioselective manner. Mechanistic studies indicate that the 1,4-aryl migration proceeds through a radical pathway. [ABSTRACT FROM AUTHOR]

A novel copper-catalyzed one-pot functionalization of homopropargylic alcohols that involves trifluoromethylation, aryl migration, and formation of a carbonyl moiety has been developed. This reaction constitutes the first direct conversion of homopropargylic alcohols into CF3-containing 3-butenal or 3-buten-1-one derivatives in a regioselective manner. Mechanistic studies indicate that the 1,4-aryl migration proceeds through a radical pathway. [ABSTRACT FROM AUTHOR]

Regioselective trifluoromethylation–cyclization: A method for copper‐catalyzed trifluoromethylation–cyclization of simple enynes using the CC triple bond as a nucleophile is reported for the first time (see scheme). The reaction proceeds efficiently in a highly regioselective manner to give various 5‐ or 6‐exo‐dig carbocycles and heterocycles in moderate to high yields. [ABSTRACT FROM AUTHOR]

Uranium extraction and recovery play a critical role in guaranteeing the sustainable nuclear energy supply and protecting the environmental safety. The ideal uranium sorbents possess high adsorption capacity, excellent selectivity and reusability, as well as outstanding antimicrobial property, which are greatly desired for the real application of uranium extraction from seawater. To address this challenge, a novel magnetic core-shell adsorbent was designed and fabricated by a facile method. The obtained amidoximed Fe 3 O 4 @TiO 2 particles (Fe 3 O 4 @TiO 2 -AO) achieved equilibrium in 2 h and the maximum adsorption capacity calculated from Langmuir model is 217.0 mg/g. The adsorption kinetics followed the pseudo-second-order model. Meanwhile, the Fe 3 O 4 @TiO 2 -AO exhibited great selectivity when competitive metal ions and anions coexisted. In addition, the magnetic Fe 3 O 4 @TiO 2 -AO could be conveniently separated and collected by an external magnetic field, the regeneration efficiency maintained at 78.5% even after ten adsorption-desorption cycles. In natural seawater, the uranium uptake reached 87.5 μg/g in 33 days. Furthermore, the TiO 2 contained adsorbent showed effective photo induced bactericidal properties against both E. coli and S. aureus. The Fe 3 O 4 @TiO 2 -AO with great U(VI) adsorption performance is highly promising in uranium extraction and reclamation. [Display omitted] • Photoinduced antimicrobial Fe 3 O 4 @TiO 2 -AO is prepared. • Fe 3 O 4 @TiO 2 -AO can selectively and efficiently adsorb and separate uranium (VI). • Fe 3 O 4 @TiO 2 -AO has high reusability and outstanding stability. • Fe 3 O 4 @TiO 2 -AO has good uranium adsorption performance in natural seawater. • Fe 3 O 4 @TiO 2 -AO showed effective photo induced bactericidal properties. [ABSTRACT FROM AUTHOR]

Abstract: Using the solution phase method without any surfactants or templates, the hierarchical of Cu2Cl(OH)3 microspheres were synthesized by freeze drying. The size and surface area of the microspheres are ca. 1–2µm and 76.61m2 g−1, respectively. A possible formation mechanism is presented based on the experimental results. Methylene blue was chosen to investigate the adsorption capacity of the as-prepared adsorbent. The effects of various experimental parameters, such as pH, initial dye concentration, and contact time were investigated. The results showed that the dye removal increased with the increasing in the initial concentration of the dye and also increased in the amount of microspheres used and initial pH. Adsorption data fitted well with the Freundlich adsorption isotherm. The thermodynamic analysis presented the exothermic, spontaneous and more ordered arrangement process. The microspheres could be employed effective for removal of dyes from aqueous solution. [Copyright &y& Elsevier]

Acrylic acid graft onto corn starch with excellent water holding capacity were successfully synthesized and employed for copper ions removal in aqueous solution. N, N′-methylenebisacrylamide and potassium persulfate effectively worked as cross-linking agent and the reaction initiator for copolymerization reaction, respectively. The data of FTIR confirmed that acrylic acid has been grafted onto starch. The effect of time on the water holding performance was investigated, and its maximum value was 96.6 g/g. The copolymers were dispersed in aqueous solution of Cu2+ ions and form polymer-copper ions complex. The copper ions removal capacity of grafted starch was investigated by UV-visible spectrophotometry as a function of pH, water holding capacity, the content of NaCl, and the initial concentration of copper ions. In the presence of NaCl, the highest copper ions removal capacity was 2.56 mmol copper ions per gram of grafted starch, and 85.3% of copper ions have been removed. The isothermal study indicated that the adsorption data could be well modeled by Langmuir isotherms. [ABSTRACT FROM AUTHOR]

A platinum-catalyzed cascade heterocyclization and formal [3+2] cycloaddition reaction of 2-(1-alkynyl)-3-aryl-2-propenals and arylethenes has been developed. This cyclization reaction shows excellent regioselectivity to obtain highly substituted 4 H-cyclopenta[ b]furans in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

Abstract: Performance of the novel fiber-ball filter was investigated for the treatment of high-turbidity surface water. Impact of different operating parameters, such as coagulant type, coagulant dose and filtration velocity on the effluent turbidity, dissolved organic carbon (DOC) and head loss, as well as the particle removal characteristics were studied. The clean-bed filtration results showed that the fiber-ball filters had a great potential for the removal of turbidity matters. Addition of polymeric aluminum ferric chloride (PAFC) enhanced the removal of effluent turbidity and DOC, while the head loss was also increased. The effluent turbidity could be <0.5NTU and the removal efficiency of DOC was ∼16% when the PAFC was dosed at 12mg/L. The effluent turbidity and DOC increased slightly with increasing filtration velocities (30–50m/h) due to the greater drag forces resulted from higher filtration velocities. However, the head loss was also increased. The particle removal characteristics indicated that large particles were primarily removed in the top 30cm of the filter bed and the deep depth in the bottom 20cm played an important role in preventing the occurrence of turbidity breakthrough. It was also found that particles in the size larger than 2μm could be well removed by the fiber-ball filters, implying the potential application for the removal of protozoa like Cryptosporidium (3–15μm) to meet the desired requirement for drinking water treatment during depth filtration. [Copyright &y& Elsevier]

Abstract: Occurrence and removal efficiencies of fifteen pharmaceuticals were investigated in a conventional municipal wastewater treatment plant in Michigan. Concentrations of these pharmaceuticals were determined in both wastewater and sludge phases by a high-performance liquid chromatograph coupled to a tandem mass spectrometer. Detailed mass balance analysis was conducted during the whole treatment process to evaluate the contributing processes for pharmaceutical removal. Among the pharmaceuticals studied, demeclocycline, sulfamerazine, erythromycin and tylosin were not detected in the wastewater treatment plant influent. Other target pharmaceuticals detected in wastewater were also found in the corresponding sludge phase. The removal efficiencies of chlortetracycline, tetracycline, sulfamerazine, acetaminophen and caffeine were >99%, while doxycycline, oxytetracycline, sulfadiazine and lincomycin exhibited relatively lower removal efficiencies (e.g., <50%). For sulfamethoxazole, the removal efficiency was approximately 90%. Carbamazepine manifested a net increase of mass, i.e. 41% more than the input from the influent. Based on the mass balance analysis, biotransformation is believed to be the predominant process responsible for the removal of pharmaceuticals (22% to 99%), whereas contribution of sorption to sludge was relatively insignificant (7%) for the investigated pharmaceuticals. [Copyright &y& Elsevier]

Abstract: Antibiotics and corresponding resistance genes and resistant bacteria have been considered as emerging pollutants worldwide. Wastewater treatment plants (WWTPs) are potential reservoirs contributing to the evolution and spread of antibiotic resistance. In this study, total concentrations of tetracycline and sulfonamide antibiotics in final effluent were detected at 652.6 and 261.1ng/L, respectively, and in treated sludge, concentrations were at 1150.0 and 76.0μg/kg dry weight (dw), respectively. The quantities of antibiotic resistance genes and antibiotic resistant bacteria in final effluent were quantified in the range of 9.12×105–1.05×106 gene abundances /100mL (genomic copies/100mL) and 1.05×101–3.09×103 CFU/mL, respectively. In treated sludge, they were quantified at concentrations of 1.00×108–1.78×109 gene abandances/100mL and 7.08×106–1.91×108 CFU/100mL, respectively. Significant reductions (2–3 logs, p <0.05) of antibiotic resistance genes and antibiotic resistant bacteria were observed between raw influent and final effluent. The gene abundances of tetO and tetW normalized to that of 16S rRNA genes indicated an apparent decrease as compared to sulI genes, which remained stable along each treatment stage. Significant correlations (R2 =0.75–0.83, p <0.05) between numbers of resistant bacteria and antibiotic concentrations were observed in raw influent and final effluent. No significance (R2 =0.15, p >0.05) was found between tet genes (tetO and tetW) with concentration of tetracyclines identified in wastewater, while a significant correlation (R2 =0.97, p <0.05) was observed for sulI gene and total concentration of sulfonamides. Correlations of the quantities of antibiotic resistance genes and antibiotic resistant bacteria with corresponding concentrations of antibiotics in sludge samples were found to be considerably weak (R2 =0.003–0.07). [Copyright &y& Elsevier]

Abstract: Antidepressant activity-guided fractionation of the MeOH extract of Valeriana fauriei Briq. roots resulted in the isolation of two new germacrane-type sesquiterpenes (1–2) in addition to seven known ones (3–9). Their structures were elucidated as 1β,10α-dihydroxyl-8α-acetoxyl-10β,11,11-trimethyl-4-formyl-bicyclogermacren-E-4(5)-ene (1), 1β-hydroxyl-8α-acetoxyl-11,11-dimethyl-4-formyl-bicyclogermacren-E-4(5),10(14)-diene (2), bicyclo[8,1,0]5β-hydroxyl-7β-1acetoxyl-5α,11,11′-trimethyl -E-1(10)-ene-4α,15-olide (3), 8α-acetoxyl-3α,4α,10-trihydroxyl-guaia-1(2)-ene-12,6α-olide (4), 2-Ethylhexyl-4-hydroxybenzoate (5), 11αH-gemacra-1(10)E,4Z-diene-3-one-12,6α-olide (6), β-Sitoterol (7), isovaleric acid (8), isoborneol acetate (9), using a combination of UV, IR, mass spectroscopy, 1D and 2D NMR spectroscopy. The antidepressant activity of compounds 1–4 was investigated by the FST on mice. Among them, compounds 3 and 4 showed the significant antidepressant activity (*, P <0.01). [Copyright &y& Elsevier]

Nowadays comb-type polyacrylamides are deemed to be the most promising oil-displacing agent in the field of enhanced oil recovery (EOR). We describe the synthesis of a nonionic, amphiphilic macromer (OPAE) with acrylic acid (AA) and t-octylphenoxypolyoxyehylene (OP) by an esterification reaction. The macromer was then copolymerized with acrylamide (AM) under a free radical initiator system and a comb-type modified polyacrylamide (MPAM) was obtained. The structures of OPAE and the MPAM were characterized by Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR) and dynamic laser light scattering. In order to compare with partially hydrolyzed polyacrylamide (HPAM), the aqueous solution of the MPAM had a higher apparent viscosity, especially in brine. We suggest that the reason was that the branched chains enhanced the rigidity of the MPAM, and made the molecules have a larger hydrodynamic radius, especially in brine, endowing the copolymer with excellent salt tolerance. [ABSTRACT FROM AUTHOR]

Abstract: Effects of different pretreatment protocols in (NH4)2HPO4 activation of rice straw on porous activated carbon evolution were evaluated. The pore structure, morphology and surface chemistry of obtained activated carbons were investigated by nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that pretreatment combining impregnation with (NH4)2HPO4 and preoxidation could significantly affect the physicochemical properties of prepared activated carbons. The apparent surface area and total pore volume as high as 1154m2/g and 0.670cm3/g were obtained respectively, when combined process of impregnation followed by preoxidation at 200°C and activation at 700°C was carried out. Meanwhile, the activated carbon yield and maximum methylene blue adsorption capacity up to 41.14% and 129.5mg/g were achieved, respectively. The results exhibited that (NH4)2HPO4 could be an effective activating agent for producing activated carbons from rice straw. [ABSTRACT FROM AUTHOR]

The multi-hydroxymethyl structure of resol makes it suitable for connecting two or more polyacrylamide chains as a crosslinker in oil recovery applications, but control of the structure and composition of the resol, whether in practice or theory, is still a controversial problem. In the present research, a series of resol prepolymers synthesized with different amounts and types of catalysts, formaldehyde to phenol molar ratio, reaction temperature and charging steps were characterized by high-performance liquid chromatography. It is found that the compositions of the resols barely changed with almost all the varying conditions, but the contents of each component were greatly affected by the variation of reaction conditions. Finally, the best conditions for preparing resol crosslinker were obtained. [ABSTRACT FROM AUTHOR]

Abstract: In the present phytochemical study on the leaves of Crataegus pinnatifida, a new monoterpene glycoside, (3S,5R,6R,7E,9R)-3,6-epoxy-7-megastigmen-5,9-diol-9-O-β-Dglucopyranoside(6) and a new sesquilignan glycoside, acernikol-4’’-O-β-D-glucopyranoside (15), together with thirteen known compounds were isolated. [ABSTRACT FROM AUTHOR]

Arc volcanic rocks are important products of the subduction factory in convergent plate margins and contribute significantly to crust building in the evolving Earth. Southwest Japan provides a window to gain insights into the ongoing subduction-related processes and the early stages of crust building. In this study, we investigate a suite of volcanic rocks from the central segment of the Setouchi volcanic belt (SVB) including dacites and andesite from northeast Shikoku island in southwestern Japan based on petrologic, geochemical, zircon U--Pb, REE (rare-earth element), and Lu--Hf analyses. The dacites and andesite from this region are peraluminous, medium-K, and calc-alkalic, with LREEs (light rare-earth elements) enrichment and depleted in HREEs (heavy rare-earth elements) and HFSEs (high field-strength elements). Two groups of zircon grains occur in these volcanic rocks as revealed from U--Pb studies. The older magmatic zircon grains are of late Cretaceous age and show typical oscillatory zoning yielding 206Pb/238U age peaks at 83.6 Ma with dominantly negative εHf(t) values (−3.7 to +0.9), indicating older reworked crustal sources. The second group is represented by thin elongated prismatic grains with banded structure, which yield 206Pb/238U age peaks at 13.8 Ma and displaying more positive εHf(t) values (+2.4 to +7.7), indicating juvenile sources. A compilation and comparison of the available geochemical and geochronological data on the volcanic suites in the SVB reveal a common source for the coeval island-arc volcanic rocks (andesite-dacites-rhyolite) and HMA (high magnesium andesites). Compared with the HMA, the other volcanics are more evolved through crustal contamination and fractionation. [Display omitted] • Dacites and andesite from SVB are calc-alkalic and peraluminous. • Zircon morphology and U--Pb ages constrain the timing of volcanism at 13.75 Ma. • Zircon xenocrysts of ca. 83 Ma from Ryoke basement suggest crustal interaction. • Positive εHf(t) values suggest juvenile arc magmatism. • Coeval HMA and non-HMA volcanism correlated to source heterogeneity. [ABSTRACT FROM AUTHOR]

Hydrogel produced by cross-linking a dilute or semidilute partially hydrolyzed polyacrylamide solution with water soluble phenolic aldehyde has been characterized by rheology studies. First, the gelation process and the structure of the hydrogel were studied by steady shear flow experiments. Rheological results indicate the gelation process of a dilute HPAM solution includes three stages: a short induction period, an acceleration period and a long termination period. Compared with the polymer solution, cross-linked hydrogel displays a heterogeneous property owing to the intra and inter-molecular cross-links formed during the gelation. Second, the steady state hydrogel properties are discussed as a function of the concentration of both the polymer and the cross-linker. In contrast, the hydrogel formed in a semidilute regime is more homogeneous than that generated in a dilute regime. [ABSTRACT FROM AUTHOR]

Abstract: Fourteen isomers of hexanitrosobenzene (HNOB) have been studied using the ab initio and density functional theory (DFT). Five stable isomers (1, 2, 10, 11 and 12) were found at the DFT-B3LYP level and the furazan structure 1 commonly called BTF has the lowest energy. The geometries, frequencies, and thermodynamic functions of the five stable isomers of HNOB and the ion of BTF have been calculated at the B3LYP/6-31G* level. Calculations have also been carried out on BTF at BLYP and MP2 levels with the 6-31G* basis set for comparison. Electron affinity of BTF was predicted to be 185.52kJ/mol in gas phase at 298.15K. Natural bonding orbital analysis was performed and the bonding condition of the stable isomers was described. The natural charges have been used to estimate the binding energies of 1s electrons of atoms in these isomers, and the calculated results of BTF were compared with the experimental results and were found to be satisfactory. The equilibrium contents of various stable isomers were estimated. 1 has the largest content (mole fraction is 0.29) and the contents of 10–12 are very close in magnitudes (0.22–0.23) and only slightly lower than that of 1, but the content of 2 is very low (0.02). The heats of formation of 1, 2, 10, 11 and 12 have been deduced from the two designed reactions, and the results are 489.53, 1570.04, 496.88, 515.67 and 507.68kJ/mol, respectively. The possible reason for the change in the color of BTF upon exposure to light was given. [Copyright &y& Elsevier]

[Display omitted] • Archean Ocean Plate Stratigraphy identified from the Wutai Complex. • Pelagic, hemipelagic and turbidite sequence accreted onto arc. • Zircon U-Pb-Hf data suggest Neoarchean intra oceanic arc building. • Subduction initiation in the late Mesoarchean. • Prolonged subduction-accretion culminating in late Paleoproterozoic collision. Ocean Plate Stratigraphy (OPS) is the travelogue of the oceanic lithosphere from its birth at the Mid Ocean Ridge to its demise at the subduction zone in convergent plate margins. Here we present an OPS succession preserved onland in the Wutai Complex of the North China Craton (NCC), representing a prolonged subduction-accretion-collision system and continental growth during the Neoarchean-Paleoproterozoic. The OPS succession in Wutai includes metabasalts and banded iron formation representing the pelagic sequences together with intercalated metacarbonates. Phyllite, greenschist, and mica schist represent the hemipelagic sequence. Quartzite and conglomerate correspond to the turbidite sequence, with a progressive southward accretion towards a magmatic arc in the north. We present results from petrological, geochemical, zircon U-Pb, REE, and Lu-Hf studies from representative rocks in the OPS sequence of the Wutai Complex. The trace elements including the rare-earth element (REE) data of the metabasalt show transitional features between normal mid-ocean ridge basalt (N-MORB) and enriched mid-ocean ridge basalt (E-MORB). The REY (lanthanide elements and Y) data of the banded iron formation (BIF), greenschists, and phyllite suggest the interaction of high-temperature hydrothermal fluids and seawater. Magmatic zircon grains from the quartzite show 206Pb/207Pb upper intercept age of 2443 ± 21 Ma, whereas zircon grains in the phyllite show upper intercept age of 2494 ± 32 Ma, with minor xenocrysts with older ages of 2726 ± 46 Ma and 2672 ± 48 Ma. Zircon grains in the metaconglomerate show upper intercept age of 2569 ± 32 Ma. Those from the siliceous and intercalated bands in the BIF yield upper intercept ages of 2583 ± 34 Ma and 2524 ± 49 Ma. The zircon Lu-Hf data on zircon grains from the BIF, phyllite, quartzite, and metaconglomerate all show positive εHf(t) values (+1.3 to +7.4) in the range of depleted mantle to new crust, suggesting Neoarchean intra oceanic arc subduction. Combined with the zircon U-Pb and Hf isotopic data previously reported from the Wutai Complex, we infer the following four tectonic evolution stages: ca. 2800 Ma subduction initiation, ca. 2750–2300 Ma arc-accretionary complex, ca. 2300–2100 Ma back-arc rifting, and ca.1900–1750 Ma arc-continent collision. The metavolcanics and part of the metasedimentary rock assemblages in the Wutai Complex represent a deformed and dismembered OPS sequence generated through northward subduction and closure of the Wutai Ocean. [ABSTRACT FROM AUTHOR]

A facile access to 4-((trifluoromethyl)thio)-2,3-dihydrofurans from unprotected homopropargylic alcohols in high regioselectivity is reported. This method is the first example of using a free hydroxy group as a nucleophile to complete a trifluoromethylthiolation/cyclization protocol with an alkyne in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Protoliths of mafic granulites and associated rocks derived from sub-alkaline tholeiitic magma. • Magmatism peaked at 3.1 Ga and occurred in a subduction-related arc setting. • High grade metamorphism at ca. 3.0 associated with collision. • Charnockites and mafic granulites represent the roots of this microblock. The Coorg Block in southern India is an archive of Paleo-Mesoarchean arc magmatism and continental building in the early Earth. Here we investigate a suite of mafic and ultramafic rocks and associated lithologies to characterize the roots of this microcontinent. We present petrologic, geochemical, as well as U-Pb and Lu-Hf data on zircon and U-Pb data on monazite from these rocks which provide insights into the petrogenesis of the rocks as well as the timings of magmatism and subsequent metamorphism. The geochemical features of the mafic granulites indicate that the rock suite was derived from the fractionation of a sub-alkaline tholeiite magma. Most of the rocks correspond to arc setting in a subduction-related tectonic regime. The rocks exhibit relative enrichment in LILE, Pb, and LREE with depletion in HFSE such as Nb and Ta suggesting partial melting of a metasomatized mantle wedge. Their high LILE/HFSE and LREE/HFSE ratios indicate slab dehydration and mantle wedge melting in typical island arc settings. The overall trace element and REE patterns of the rocks indicate that the source magma of the ultramafic and mafic rocks might have been derived from a refractory mantle source followed by the metasomatic enrichment of lithospheric mantle wedge by incompatible elements through the influx of subduction-derived fluids/melts. We present comprehensive zircon U-Pb data and Lu-Hf data on a suite of mafic granulite, garnet-bearing granulite, tremolite actinolite schist, charnockite, and anorthositic gabbro as well as monazite U-Pb data from a charnockite sample. Most zircon grains show cores with magmatic crystallization features and many grains are mantled by metamorphic rims. The age data show a prominent peak at 3.1 Ga for most of the rocks suggesting that the major crustal building in the Coorg Block occurred during the Mesoarchean. Rocks on the margins of the block were affected by the younger (Neoarchean) tectonothermal event in the surrounding blocks. The Lu-Hf isotopic data on zircon grains with ca. 3.1 Ga ages show εHf(t) values ranging from −4.4 to + 3.7 (average + 0.3). In the εHf(t) versus 207Pb/206Pb age diagram, the plots are distributed close to the CHUR line suggesting Paleo-Eoarchean juvenile magma sources. The voluminous mafic lower crust at the root of the Coorg Block is consistent with addition of mafic magmas through slab melting induced by high mantle potential temperatures in the Archean, as well as the interaction of fluids/melts with the mantle wedge. [ABSTRACT FROM AUTHOR]

Background: No consensus has been concluded with regarding to the scope of lymph node (LN) dissection for Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). This study aimed to explore risk factors for lower perigastric LN (LPLN) metastases (including no. 4d, 5, 6, and 12a LN stations) and analyze the indications for LPLN dissection. Methods: In total, 302 consecutive patients with Siewert type II and III AEG who underwent total gastrectomy (TG) were enrolled. The logistic regression model was used to perform uni- and multivariate analyses of risk factors for LPLN metastases. Kaplan–Meier curves were used for survival analysis, and log-rank tests were used for group comparisons. Basing on the guidelines of Japanese Gastric Cancer Association, the LN metastases (LNM) as well as the efficiency index (EI) of each LN station was further evaluated. Results: The independent risk factors for LPLN metastases in patients with Siewert type II and III AEG were distance from the esophagogastric junction (EGJ) to the distal end of the tumor (> 4.0 cm), preoperative carcinoembryonic antigen (CEA) (+), pT4 stage, and HER-2 (+). LPLN metastases was an independent risk factor for overall survival following TG. The LNM and EI of LPLN were 8.6% and 2.31%, respectively. The LNM of LPLN > 10% under the stratification of the distance from the EGJ to the distal end of the tumor (> 4.0 cm), pT4, preoperative CEA (+), and HER-2 (+) exhibited EI values of 3.55%, 2.09%, 2.51%, and 3.64%, respectively. Conclusions: LPLN metastases was a malignant factor for the prognosis of patients with Siewert type II and III AEG. For patients with preoperative CEA (+), pT4 stage, HER-2 (+), and the distance from the EGJ to the distal end of the tumor (> 4.0 cm), TG with LPLN dissection is prioritized for clinical recommendation. [ABSTRACT FROM AUTHOR]

Nitrogen (N) shortage poses a great challenge to the implementation of in situ bioremediation practices in mining-contaminated sites. Diazotrophs can fix atmospheric N2 into a bioavailable form to plants and microorganisms inhabiting adverse habitats. Increasing numbers of studies mainly focused on the diazotrophic communities in the agroecosystems, while those communities in mining areas are still not well understood. This study compared the variations of diazotrophic communities in composition and interactions in the mining areas with different extents of arsenic (As) and antimony (Sb) contamination. As and Sb co-contamination increased alpha diversities and the abundance of nifH encoding the dinitrogenase reductase, while inhibited the diazotrophic interactions and substantially changed the composition of communities. Based on the multiple lines of evidence (e.g., the enrichment analysis of diazotrophs, microbe-microbe network, and random forest regression), six diazotrophs (e.g., Sinorhizobium, Dechloromonas, Trichormus, Herbaspirillum, Desmonostoc, and Klebsiella) were identified as keystone taxa. Environment-microbe network and random forest prediction demonstrated that these keystone taxa were highly correlated with the As and Sb contamination fractions. All these results imply that the above-mentioned diazotrophs may be resistant to metal(loid)s. [ABSTRACT FROM AUTHOR]

• Photocatalytic membrane was prepared with aCN and PDA in a facile way. • The membrane coupled the effect of filtration and photocatalysis. • The membrane exhibited excellent removal ratio for dye and antibiotic. • The removal mechanism of the membrane was investigated. Graphite carbon nitride (gCN) has attracted extensive attention due to excellent 2D structure and photocatalytic performance since it was discovered. In this work, the novel membrane was fabricated with acidified graphite carbon nitrogen (aCN) as a selective layer and dopamine (DA) as a cushion layer on a polysulfone (PS) membrane. The removal effect of aCN membrane on methyl blue and ciprofloxacin has improved with the excellent photocatalytic property of aCN. Meanwhile, SEM, XRD, FTIR spectra and DLS was performed to investigate the morphology, structure and property of the obtained membranes. The results showed that dopamine not only provided adhesion for aCN, but also enhanced photoelectron transfer. The membrane with optimized conditions aided by the structure and photocatalytic performance of aCN exhibited great removal rates for both methyl blue (97.2%) and ciprofloxacin (99.4%). The above experiments proved the advantages of aCN in the removal of dyes and antibiotics in coupling filtration and photocatalysis. [ABSTRACT FROM AUTHOR]

The South Andaman Island is located on the southeastern fringe of the Indian plate. Tectonically, the islands are associated with the Burma-Andaman-Java subduction zone of the Indonesian arc system. Several Mesozoic ophiolitic exposures are preserved in the Burma-Andaman-Java subduction zone. This study reports new petrological, geochemical, and zircon U-Pb geochronological data for the diabases, gabbros, anorthosites, and harzburgites of the ophiolite suite exposed in the South Andaman Island. The diabase is composed of plagioclase and clinopyroxene exhibiting ophitic textures. Anorthosite mainly contains plagioclase (> 90 vol%), pyroxenes and Fe-oxides. Gabbros have plagioclases and clinopyroxenes occurring as the major minerals. Harzburgites consist of olivine, orthopyroxene, clinopyroxene and spinel. Geochemical investigation reveals that these rocks were formed through crystal fractionation and accumulation processes from partial melt generated from a spinel lherzolite source. Gabbro, diabase, and anorthosites are formed by ∼1–5% melting of the, whereas depleted harzburgites were generated by slightly higher degrees of partial melting (∼10–20%) of the spinel lherzolite source. Trace element modelling reveals the influence of mid-oceanic ridge basalt (MORB)-melt interaction and subduction-related mantle alterations. The anorthosite and gabbro samples yield zircon 206Pb / 238U weighted mean ages of 93.2 ± 1.0 Ma and 442.5 ± 4.0 Ma, 383.9 ± 3.3 Ma respectively. However, the harzburgite sample records multiple age population including Paleo-Mesoproterozoic grains ranging in age from 1216 to 1931 Ma as well as Neoproterozoic and Phanerozoic grains of 607 Ma, 594 Ma, 237 Ma, 105 Ma, and 85 Ma suggesting a long-lived supra subduction zone in the Burma-Andaman-Java subduction zone where the South Andaman ophiolite suite was formed, evolved, and was emplaced. [Display omitted] • First report on the geochemical characteristics of diabase and anorthosites from the South Andaman Ophiolite suite. • Magmatic zircons from the anorthosite yields an age of 93.2 ± 1.0 Ma • First report on age of an ophiolitic anorthosite from the Indian ophiolite occurrences. • Additional novel geochemical and geochronological data on gabbros and harzburgites South Andaman Ophiolite suite. • Geochronological results imply a long lived supra subduction zone in the Burma-Andaman-Java subduction zone. [ABSTRACT FROM AUTHOR]

• Discovery of a suprasubduction zone ophiolite suite with near-complete stratigraphy. • Geochemical features suggest mantle source and MORB-IAT setting. • Age peaks at 2486 Ma and 1832 Ma correspond to emplacement and metamorphism. • Markedly positive ɛHf(t) values suggest Neoarchean depleted mantle (juvenile) source. • Evaluation of Archean–Paleoproterozoic subduction system in the NCC. The North China Craton (NCC) offers a window to Archean–Paleoproterozoic crustal evolution. Following the amalgamation of microblocks during Neoarchean, the NCC witnessed another protracted Wilson cycle in the Paleoproterozoic with subduction-accretion-collision process. Here we report a newly identified suprasubduction zone ophiolite suite from the Miyun complex in the NCC where a rare and near-complete ophiolite succession is preserved including serpentinite, lherzolite, olivine clinopyroxenite, websterite, gabbro, dolerite, diorite, monzonite, metabasalts and trondhjemite, in association with Banded Iron Formation (BIF). The geochemical features of the suite are consistent with those of suprasubduction ophiolite complexes, with the mafic and intermediate members displaying Island Arc Tholeiite (IAT) and Mid-Ocean Ridge Basalt (MORB) affinity. Zircon grains from lherzolite define three groups of 207Pb/206Pb weighted mean ages at 2500 ± 12 Ma marking the formation age, and 2237 ± 47 Ma, and 1843 ± 30 Ma representing subsequent thermal events. The majority of zircon grains in olivine clinopyroxenite, gabbro, and quartz monzonite yield 207Pb/206Pb weighted mean ages of 2510 ± 19 Ma, 2495 ± 10 Ma, and 2486 ± 21 Ma respectively. Those from the trondhjemite show weighted mean age of 2476 ± 9.4 Ma. The compiled age data from all the rock types in the Miyun suite show two distinct age peaks at ca. 2486 Ma and 1832 Ma, corresponding to the timing of magma differentiation and subsequent metamorphism. The zircon Lu-Hf isotope data display distinct positive ɛHf(t) values in the range 0.35–7.05, suggesting magma derived from Neoarchean to Paleoproterozoic depleted mantle (juvenile) source. The zircon T DM ages show a peak at 2670 Ma, confirming Neoarchean components. The timing of magma formation in the Miyun ophiolite is broadly identical to those of the other rare Neoarchean – early Paleoproterozoic ophiolite suites described from the NCC including those from Yishui and Zunhua. Furthermore, evidence from the recently reported Alaskan-type intrusions and arc root mafic-ultramafic complexes around Miyun complex with ages in the range of 2.4–2.0 Ga suggest continued subduction-related magmatic processes, with final collision in latest Paleoproterozoic at around 1.84 Ga. We propose that following the assembly of ancient microblocks along multiple zones of ocean closure marked by major greenstone belts of 2.6–2.5 Ga, and high-grade metamorphism along the margins of the microblocks during Archean–Paleoproterozoic transition, the NCC went through another major Wilson cycle from early to late Paleoproterozoic involving prolonged subduction, accretion and collision of larger crustal blocks and intervening arc complexes, leading to final cratonization. [ABSTRACT FROM AUTHOR]

• BIFs and iron-bearing carbonate rocks correlated to Archean submarine hydrothermal system. • The δ34S V-PDB values compare with the features of typical Algoma-type BIFs. • The trace element features including enrichment in Ni, As, Se, Te, and Pb are also consist with Algoma type. • The δ13C V-PDB and δ18O V-PDB values of the carbonates confirm an oceanic setting. The major archive of iron deposits in China occur within Precambrian banded irons formations (BIFs). Here we investigate the Wutai complex that represents an Archean to Paleoproterozoic subduction-related arc system between the Ordos and Qianhuai micro-blocks of the central North China Craton (NCC). We report the carbon and oxygen isotopes of calcites from carbonate-rich BIFs, and in situ trace elements (LA-ICP-MS) and sulfur isotopes (ion probe) of pyrites from sulfidic BIFs and carbonate samples with an aim to characterize the nature and genesis of the iron deposits associated with these rocks. The δ13C V-PDB , δ18O V-PDB and δ18O V-SMOW of calcites range from −2.4‰ to −1.1‰, −20.4‰ to −19.3‰ and 9.9‰ to 11‰ respectively, displaying Archean greenstone belt and marine carbonate settings. Pyrite from the BIFs and carbonates are enriched Ni, As, Se, Te, and Pb. Their δ34S CDT values range from −8.8‰ to 7.9‰ with a peak at 0.0‰, comparing with the features of typical Algoma-type BIFs. Our study provides insights into the depositional environment of the BIFs in the Wutai Complex. [ABSTRACT FROM AUTHOR]

• Greenstone – volcanic tuff – BIF – phyllite succession representing subduction-accretion. • Zircon U-Pb data indicate active convergent margin during 2951–2471 Ma with peak arc building at around 2.5–2.6 Ga. • The timing of metamorphism is constrained between 1906 and 1845 Ma. • Positive εHf (t) values indicate new crustal additions. • Wutai arc was built during ca. 2.87–2.45 Ga, coinciding with initial cratonization of NCC. The Wutai complex is located within the Trans–North China Orogen (TNCO) which marks the collision zone between the Eastern and Western Blocks of the North China Craton (NCC). Here we investigate the timings and mechanisms of Precambrian arc building in Wutai from a suite of newly identified greenstone – felsic tuff – Banded Iron Formation (BIF) – phyllite sequence. Zircon grains from the felsic tuff layer intercalated within the greenstones provide robust constraints on the timing of BIF deposition. Geochemical features of the greenstones and felsic tuff suggest E - MORB and volcanic arc affinity, whereas the BIFs are of submarine hydrothermal origin. Zircon grains in the greenstones define an upper intercept age of 2951 ± 41 Ma and a lower intercept age of 1845 ± 190 Ma. Those from the felsic tuff show 207Pb/206Pb weighted mean age of 2557 ± 10 Ma, whereas those from the BIF intercalated with felsic tuff shows an age of 2585 ± 14 Ma. Metamorphic zircon grains in the BIF define two age populations of ca. 2471 and 1906 Ma. Zircon grains in the phyllite yield an age of 2594 ± 14 Ma. Kernel density plots define age peaks at 2873 and 2578 Ma marking the major phase of arc building in Wutai. Zircon εHf (t) values are mostly positive, in the range of 3.15–7.72, suggesting new crustal growth from juvenile/depleted mantle components. Our study provides insights into the Mesoarchean to Neoarchean crust building through subduction-related arc magmatism, followed by Paleoproterozoic metamorphism in the North China Craton. [ABSTRACT FROM AUTHOR]

A photoredox-catalyzed alkylarylation of activated alkenes via a radical C–C bond cleavage/Truce–Smiles rearrangement cascade is developed. The protocol features mild and redox-neutral conditions, broad substrate scope and excellent functional group compatibility, providing a facile and efficient approach to the long-chain distal keto-amides with all-carbon quaternary centers at the alpha position. [ABSTRACT FROM AUTHOR]