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The biogeochemical cycle of iron is of great importance to living organisms on Earth, and dissimilatory metal-reducing bacteria (DMRB) with the capability of reducing hematite (α-Fe2O3) by outer-membrane (OM) cytochromes play a great role in the iron cycle. However, the dynamic binding of cytochromes to α-Fe2O3 at the molecular level and the resulting impact on the photon-to-electron conversion of α-Fe2O3 for the iron cycle are not fully understood. To address these issues, two-dimensional IR correlation analysis coupled with molecular dynamics (MD) simulations was conducted for an OmcA-Fe2O3 system as OmcA bonds stronger with hematite in a typical DMRB,Shewanella. The photoelectric response of α-Fe2O3 with the OmcA coating was evaluated at three different potentials. Specifically, the binding groups from OmcA to α-Fe2O3 were in the sequence of carboxyl groups, amide II, and amide I. Further MD analysis reveals that both electrostatic interactions and hydrogen bonds played essential roles in the binding process, leading to the structural changes of OmcA to facilitate iron reduction. Moreover, the OmcA coating could store the photogenerated electrons from α-Fe2O3 like a capacitor and utilize the stored electrons for α-Fe2O3 reduction in dark and anoxic environments, further driving the biogeochemical cycle of iron. These investigations give the dynamic information on the OM protein/hematite interaction and provide fundamental insights into the biogeochemical cycle of iron by taking the photon-induced redox chemistry of iron oxide into consideration.

As one of the extensively used feed additives in livestock and poultry breeding, p-arsanilic acid (p-ASA) has become an organoarsenic pollutant with great concern. For the efficient removal of p-ASA from water, the combination of chemical oxidation and adsorption is recognized as a promising process. Herein, hollow/porous Mn-Fe-mixed oxide (MnFeO) nanocubes were synthesized and used in coupling with peroxymonosulfate (PMS) to oxidize p-ASA and remove the total arsenic (As). Under acidic conditions, both p-ASA and total As could be completely removed in the PMS/MnFeO process and the overall performance was substantially better than that of the Mn/Fe monometallic system. More importantly, an interface-promoted direct oxidation mechanism was found in the p-ASA-involved PMS/MnFeO system. Rather than activate PMS to generate reactive oxygen species (i.e., SO4·-, ·OH, and 1O2), the MnFeO nanocubes first adsorbed p-ASA to form a ligand-oxide interface, which improved the oxidation of the adsorbed p-ASA by PMS and ultimately enhanced the removal of the total As. Such a direct oxidation process achieved selective oxidation of p-ASA and avoidance of severe interference from the commonly present constituents in real water samples. After facile elution with dilute alkali solution, the used MnFeO nanocubes exhibited superior recyclability in the repeated p-ASA removal experiments. Therefore, this work provides a promising approach for efficient abatement of phenylarsenical-caused water pollution based on the PMS/MnFeO oxidation process.

Incorporating artificial photosensitizers with microorganisms has recently been recognized as an effective way to convert light energy into chemical energy. However, the incorporated biosystem is usually constructed in an extracellular manner and is vulnerable to the external environment. Here, we develop an intracellular hybrid biosystem in a higher organism protozoa Tetrahymena pyriformis, in which the in vivo synthesized CdS nanoparticles trigger photoreduction of nitrobenzene into aniline under visible-light irradiation. Integrating a photosensitizer CdS into T. pyriformis enables the photosensitizer CdS, inherent nitroreductase, and the cytoplasmic reductive substance in T. pyriformis to synergistically engage in the photocatalysis process, generating a greatly enhanced aniline yield with a 40-fold increment. Moreover, building an intracellular hybrid biosystem in mutant T. pyriformis could even grant it new capability of reducing nitrobenzene into aniline under visible-light irradiation. Such an intracellular hybrid biosystem paves a new way to functionalize higher organisms and diversify light energy conversion.

Members of the Shewanella genus play important roles in bioenergy generation and environmental bioremediation, but their practical applications in engineered systems are still limited due to the la...

Graphitic carbon nitride (gCN) has attracted increasing interest in photocatalysis because of its visible-light-responsive ability, environment-friendliness, low cost and ease of large-scale production. However, its practical application is restricted by its insufficient light absorption, relatively small surface area and low charge separation efficiency. In this work, a post-P-doped gCN nanosheet (gCN-P (post)) with a controllable morphology was successfully synthesized and highly-active P sites were introduced by C/P substitution. The formed porous nanosheet structure greatly increased the specific surface area and exposed more active sites to favor the photocatalytic reaction. gCN-P (post) exhibited excellent visible light photoactivity toward bisphenol A (BPA) degradation with a much higher reaction rate than pristine gCN and other P-doped g-C3N4 composites. Doping P resulted in a narrowed band gap of gCN with enhanced light-harvesting and improved reduction capacity of electrons, which facilitated the reduction of molecular oxygen and the formation of more high-powered oxidative species. The post-P doping could maintain the morphology of gCN nanosheets with a high yield and simultaneously optimize the electronic orbital distribution of the triazine ring. The high BPA mineralization efficiency and preferable photostability capacity further confirmed its application potential. This work provides a promising approach for efficient water and wastewater treatment with rationally designed visible-light-responsive photocatalysts.

We propose a new strategy to make an active and stable Ni-based catalyst which can be operated in a wide range of reaction temperatures. The ordered mesoporous alumina (OMA) with confined Ni in the pore wall (Ni-OMA) was prepared via the one-pot evaporation induced self-assembly method. By using the incipient impregnation method, different amounts of free Ni were loaded over Ni-OMA (Ni/Ni-OMA) at a fixed total NiO content of 15 wt%. Characterization results confirmed the formation of well-structured Ni-OMA, and the ordered structure was still well preserved even after impregnating NiO at a content of as high as 12 wt%. The catalysts were evaluated for the CO methanation as a model reaction under varied conditions. Importantly, the activity and stability of Ni/Ni-OMA for the titled reaction were significantly regulated by simply changing the ratio of the confined to free Ni. Over the optimum catalyst of NiO (2 wt%)/NiO (13 wt%)-OMA, the high activity at a temperature of as low as 300 °C was achieved with the space-time yield of methane over 7.6 g gcat−1 h−1 while a long-term stability for a time-on-stream of 400 h was confirmed without an observable deactivation under the conditions of 600 °C and an extremely high gas hourly space velocity of 120,000 mL g−1 h−1. The results were well explained as the integrated merits of the free Ni for a high dispersion and the confined Ni in OMA for the anti-sintering property.

Phosphorus (P) recovery from wastewater can be completed by iron-involved autotrophic denitrification via forming Fe(III)-P precipitates and/or adsorbing P onto Fe(III) oxyhydroxides. However, so far, most studies focused on the final P-containing products, while the P-capturing pathways in such a process remain unclear. In this work, autotrophic iron-dependent denitrification (AIDD) was used as a typical anoxic iron-involved P-capturing biosystem to investigate the main P recovery pathways. The AIDD biosystem showed a relatively stable capability of capturing P coupled with nitrate reduction. Direct formation of amorphous Fe(II)-P precipitates after the phosphate was fed, followed by microbially driven oxidation into Fe(III)-P minerals, was found to be the primary pathway for the P capture. In addition, adsorption of phosphate onto the formed iron oxyhydroxides also contributed to the P recovery. This work provides better understanding about recovering P in AIDD and iron-involved denitrification and highlights the important roles of iron oxidizers in the iron-related biological wastewater treatment processes.

Biotransformation of selenite to valuable elemental selenium nanoparticles (Se0) is a promising avenue to remediate seleniferous environments and simultaneously recover selenium (Se). However, the underlying oxyanion competition and selenite transformation mechanism in prokaryotes are poorly understood. In this work, the impacts of phosphate on selenite uptake and transformation were elucidated with Escherichia coli and its mutant deficient in phosphate transport as model microbial strains. Selenite uptake was inhibited by phosphate in E. coli. Moreover, the transformation of internalized Se was shifted from Se0 to toxic organo-Se with elevated phosphate levels, as evidenced by the linear combination fit analysis of the Se K-edge X-ray absorption near-edge structure. Such a phosphate-regulated selenite biotransformation process was mainly assigned to the competitive uptake of phosphate and selenite, which was primarily mediated by a low affinity phosphate transporter (PitA). Under phosphate-deficient conditions, the cells not only produced abundant Se0 nanoparticles but also maintained good cell viability. These findings provide new insights into the phosphate-regulated selenite biotransformation by prokaryotes and contribute to the development of new processes for bioremediating Se-contaminated environments, as well as bioassembly of Se0.

Exoelectrogens play the core roles in bioelectrochemical systems (BESs) because of their unique extracellular electron transfer capacity to different electron acceptors. Microbial reduction of azo dyes by exoelectrogens under anaerobic conditions has received great attention because of its eco-friendliness, low cost, and unique extracellular reduction ability. In this work, we unexpectedly found that Shewanella putrefaciens CN-32 adopted a distinctive electron transfer mechanism for bioreduction of MO (methyl orange) compared to the other exoelectrogens. MO reduction by S. putrefaciens CN-32 occurred through mechanisms that were not dependent on the known azoreductase and the Mtr (metal-reducing) respiratory pathway. Some anaerobic regulators (e.g., Fur and EtrA) and periplasmic c-type cytochromes (Sputcn32_2333) might involve in MO reduction by S. putrefaciens CN-32. The major reduction products were 4-aminobenzenesulfonic acid (4-ABA) and N, N-dimethyl-p-phenylenediamine (DPD) and the initial cell density in the reduction system affected MO reduction kinetics by S. putrefaciens CN-32. Moreover, S. putrefaciens CN-32 could utilize multiple mediators such as flavins or anthraquinone-2,6-sodium disulfonate (AQDS) to accelerate MO reduction. Our findings provide a new perspective on the reduction mechanisms of azo dyes by exoelectrogens and might facilitate more efficient utilization of them in BESs for treatments of azo dyes-polluted industrial effluents.

Photochemical oxidation is able to effectively regenerate the fouled electrode in electrochemical pollutant monitoring, while its regeneration capacity is limited by the surface-bound hydroxyl radical speciation with low activity and mobility, which is attributed to the dissociated water adsorption on hydrophilic metal oxides. In this work, fluorine-terminated {001}-exposed TiO2 single crystals (F-TiO2) are rationally designed to construct an Au-based electrochemical sensor (Au/F-TiO2) for dopamine (DA) detection in different matrices. The Au/F-TiO2 sensor exhibits an efficient and stable detection capacity in both environmental and biological samples. A superior photochemical regeneration capacity is obtained on the Au/F-TiO2 electrode with much reduced matrix effects under UV irradiation. Spectral observation, crystallographic analysis, pollutant degradation performance, radical inhibition, and surface enhanced Raman scattering tests reveal that both the fluorine-terminated surface chemical features and the bulk-free radical speciation are mainly responsible for the superior photochemical regeneration capacity of the Au/F-TiO2 electrode. Even for the real biological samples, a stable electrochemical DA detection is also achieved on the Au/F-TiO2 sensor. Our work establishes a new approach to refine electrochemical sensors for stable monitoring and provides a robust photoactive electrode substrate with high efficiency and low cost for practical applications.

Accurate, rapid, and reliable quantification of saccharides is essential for understanding their behaviors and roles in environmental processes. However, the conventional colorimetric method for saccharide quantification fails to discriminate between fructose and glucose, resulting in the misestimation of total saccharides. To solve this problem, a fluorescence approach, that is, parallel factor framework-linear regression analysis, was developed in this work to quantify the specific fluorescence signatures of the fluorescent products generated from the reaction between saccharides and sulfuric acid. The fluorescent derivatives of saccharides were recognized and the simultaneous quantification of glucose and fructose was achieved with a detection limit of 2.9 μg/mL and 1.3 μg/mL, respectively. Furthermore, 200 μg/mL of the treated sorbitol and gluconic acid only, respectively, equaled to 6 μg/mL and 3 μg/mL of the treated glucose, indicating their negligible interference for the saccharide quantification using this method. In addition, the feasibility and robustness of this method in environmental applications were validated with the recovery tests using spiked real water samples. This fluorescence-based approach offers a new tool to monitor saccharides in complex environments.

Despite the high profile of aconine in WuTou injection, there has been no preparative technology or structural studies of its salt as the pharmaceutical product. The lack of any halide salt forms is surprising as aconine contains a tertiary nitrogen atom. In this work, aconine was prepared from the degradation of aconitine in Aconiti kusnezoffii radix (CaoWu). A green chemistry technique was applied to enrich the lipophilic-poor aconine. Reaction of aconine with hydrochloride acid resulted in protonation of the nitrogen atom and gave a novel salt form (C25H42NO9 +·Cl−·H2O; aconine hydrochloride monohydrate, AHM), whose cation in the crystal structure was elucidated based on extensive spectroscopic and X-ray crystallographic analyses. The AHM crystal had a Z′ = 3 structure with three independent cation–anion pairs, with profound conformational differences among the aconine cations. The central framework of each aconine cation was compared with that of previously reported aconitine, proving that protonation of the nitrogen atom induced the structure rearrangement. In the crystal of AHM, aconine cations, chloride anions and water molecules interacted through inter-species O—H...Cl and O—H...O hydrogen bonds; this complex hydrogen-bonding network stabilizes the supramolecular structure. The seriously disordered solvent molecules were treated using the PLATON SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–18] and their atoms were therefore omitted from the refinement. Bioactivity studies indicated that AHM promoted in vitro proliferative activities of RAW264.7 cells. Molecular docking suggested AHM could target cardiotoxic protein through the hydrogen-bonding interactions. The structural confirmation of AHM offers a rational approach for improving the pharmaceutical technology of WuTou injection.

SUMMARY: The influence of different calcium source and calcium levels on the growth performance, immune organ indexes, intestinal microbiota and morphology of broiler chickens was studied. We used scallop shells to produce active dicalcium phosphate (ADP), shell powder cleaned by acetic acid (SCAC), and shell powder cleaned by distilled water (SS). A total of 300 1-d-old broiler chickens were randomly assigned to 6 treatments. The broiler chickens received a basal diet supplemented with 0.95% or 1.05% ADP, SCAC, and SS treatments until d 42. Compared with broiler chickens fed SCAC and SS, a diet with 1.05% ADP supplementation is more effective. It exhibited a greater average daily weight gain and lower feed conversion ratio (P < 0.05). The leg muscle yield were increased and the abdominal fat rate was decreased (P < 0.05). The length of the duodenum, jejunum, and ileum as well as the weight of spleen, thymus, and bursa immune organs and the activities of digestive enzymes were increased (P < 0.05). Harmful bacteria were inhibited and beneficial bacteria were increased. (P < 0.05). Furthermore, it increased the villus height and villus height to crypt depth ratio and decreased the crypt depth (P < 0.05), thereby improving intestinal development. Therefore, ADP is a potential calcium source as a kind of feed additive.

Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs. In this work, a cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), was combined with Fenton's reagent for sludge dewatering. Results show that the Fenton-CTAB conditioning significantly promotes the sludge dewatering. Using combined techniques of response surface methodology and uniform design, dosages of Fe2+, H2O2, and CTAB for water content response were optimized to be 89, 276, and 233 mg/g dry solids (DS), respectively. The water content of sludge decreased from 79.0% to 66.8% under the optimal conditions. Compared with cationic polyacrylamide, the Fenton-CTAB system exhibited superior sludge dewatering performance. To gain insights into the mechanisms involved in sludge dewatering, the effects of Fenton-CTAB conditioning on the composition of extracellular polymeric substances (EPS) and the morphology of the sludge flocs were investigated. The decomposition of EPS into some dissolved organics and the release of proteins in tightly bound EPS facilitated the conversion of bound water to free water and further reduced the water content of sludge cake. After conditioning, morphology of sludge showed aggregation. Overall, the enhanced sludge dewatering by Fenton-CTAB treatment provides an efficient way for management of sewage sludge.

Glucose electrolysis offers a prospect of value-added glucaric acid synthesis and energy-saving hydrogen production from the biomass-based platform molecules. Here we report that nanostructured NiFe oxide (NiFeOx) and nitride (NiFeNx) catalysts, synthesized from NiFe layered double hydroxide nanosheet arrays on three-dimensional Ni foams, demonstrate a high activity and selectivity towards anodic glucose oxidation. The electrolytic cell assembled with these two catalysts can deliver 100 mA cm−2 at 1.39 V. A faradaic efficiency of 87% and glucaric acid yield of 83% are obtained from the glucose electrolysis, which takes place via a guluronic acid pathway evidenced by in-situ infrared spectroscopy. A rigorous process model combined with a techno-economic analysis shows that the electrochemical reduction of glucose produces glucaric acid at a 54% lower cost than the current chemical approach. This work suggests that glucose electrolysis is an energy-saving and cost-effective approach for H2 production and biomass valorization. Renewable biomass conversion may afford high-value products from common materials, but catalysts usually require expensive metals and exhibit poor selectivities. Here, authors employ nickel-iron oxide and nitride electrocatalysts to produce H2 and to convert glucose to glucaric acid selectively.

The enterovirus 71 (EV71) 3Dpol is an RNA-dependent RNA polymerase (RdRP) that plays the central role in the viral genome replication, and is an important target in antiviral studies. Here, we report a crystal structure of EV71 3Dpol elongation complex (EC) at 1.8 Å resolution. The structure reveals that the 5′-end guanosine of the downstream RNA template interacts with a fingers domain pocket, with the base sandwiched by H44 and R277 side chains through hydrophobic stacking interactions, and these interactions are still maintained after one in-crystal translocation event induced by nucleotide incorporation, implying that the pocket could regulate the functional properties of the polymerase by interacting with RNA. When mutated, residue R277 showed an impact on virus proliferation in virological studies with residue H44 having a synergistic effect. In vitro biochemical data further suggest that mutations at these two sites affect RNA binding, EC stability, but not polymerase catalytic rate (kcat) and apparent NTP affinity (KM,NTP). We propose that, although rarely captured by crystallography, similar surface pocket interaction with nucleobase may commonly exist in nucleic acid motor enzymes to facilitate their processivity. Potential applications in antiviral drug and vaccine development are also discussed.

Supported vanadium oxides are widely used as active catalysts for a number of oxidation and oxidative dehydrogenation reactions, and the understanding the structure-function relationship is of great importance for developing more efficient vanadium oxide catalysts. In this work, atomic layer deposition (ALD) was utilized to disperse sub-monolayer VOx over a commercial γ-Al2O3 support. Characterization results indicate that highly dispersed VOx species with different structures were obtained by simply changing the number of ALD cycles. The vanadium oxides synthesized by performing 1 cycle of ALD were exclusively isolated monomeric VOx. With increasing the number of ALD cycles from 3 to 8, the polymeric VOx spices were formed, and the polymerization extent or domain size of VOx was increased. On the contrary, crystalline V2O5 besides polymeric VOx was found if the number of ALD cycles was extended to 12. Catalytic performances of ALD VOx/γ-Al2O3 were evaluated for the oxidative dehydrogenation of ethylbenzene with CO2 (CO2-ODEB), and the isolated monomeric VOx species were found to be more active and more stable than the polymeric VOx species and crystalline V2O5. By correlating the specific activity and the structural characteristics of ALD VOx/γ-Al2O3 catalysts, the V O Al bonds were concluded as the key active sites for CO2-ODEB.

Ceria, zirconia, Ce0.9Zr0.1O2, Ce0.75Zr0.25O2, and Ce0.5Zr0.5O2 samples were synthesized via the two-step hydrothermal method by using Ce(NO3)3·6H2O and Zr(NO3)4·5H2O as the precursors, respectively. The oxides were applied as catalysts for the dehydrogenation of ethylbenzene by using carbon dioxide as a soft oxidant (CO2-ODEB) at 550 °C and 0.1 MPa. Reaction results indicate that ceria was the most active catalyst while the zirconia with a cubic structure was inactive for CO2-ODEB. In the cases of the oxides by inserting Zr into CeO2, the activity indexed by either the initial ethylbenzene (EB) conversion or the calculated turnover frequency (TOF) at a time on stream of 1 h was changed in the sequence of Ce0.9Zr0.1O2 >> Ce0.75Zr0.25O2 > Ce0.5Zr0.5O2 while the decreasing pattern of the stability was observed in the order of Ce0.5Zr0.5O2 ≈ Ce0.75Zr0.25O2 >> Ce0.9Zr0.1O2. As revealed from the characterization results of XRD and Raman, the pure cubic solid solution of Ce1-xZrxO2 without any phase separations was obtained irrespective of the compositions. By correlating the characterization results, the activity of Ce1-xZrxO2 for CO2-ODEB was determined by the amount of the Ce3+ oxidized by CO2 and the rate of Ce3+/Ce4+ redox cycles. Moreover, both the coking rate and the promoting effect of the deposited coke on CO2-ODEB were responsible for the stability of Ce1-xZrxO2.

There is limited advancement on seed number per pod (SNPP) in soybean breeding, resulting in low yield in China. To address this issue, we identified PIN1 and CKX gene families that regulate SNPP in Arabidopsis, analyzed the differences of auxin and cytokinin pathways, and constructed interaction networks on PIN1, CKX, and yield-related genes in soybean and cowpea. First, the relative expression level (REL) of PIN1 and the plasma membrane localization and phosphorylation levels of PIN1 protein were less in soybean than in cowpea, which make auxin transport efficiency lower in soybean, and its two interacted proteins might be involved in serine hydrolysis, so soybean has lower SNPP than cowpea. Then, the CKX gene family, along with its positive regulatory factor ROCK1, had higher REL and less miRNA regulation in soybean flowers than in cowpea ones. These lead to higher cytokinin degradation level, which further reduces the REL of PIN1 and decreases soybean SNPP. We found that VuACX4 had much higher REL than GmACX4, although the two genes essential in embryo development interact with the CKX gene family. Next, a tandem duplication experienced by legumes led to the differentiation of CKX3 into CKX3a and CKX3b, in which CKX3a is a key gene affecting ovule number. Finally, in the yield-related gene networks, three cowpea CBP genes had higher RELs than two soybean CBP genes, low RELs of three soybean-specific IPT genes might lead to a decrease in cytokinin synthesis, and some negative and positive SNPP regulation were found, respectively, in soybean and cowpea. These networks may explain the SNPP difference in the two crops. We deduced that ckx3a or ckx3a ckx6 ckx7 mutants, interfering CYP88A, and over-expressed DELLA increase SNPP in soybean. This study reveals the molecular mechanism for the SNPP difference in the two crops, and provides an important idea for increasing soybean yield.

The seed oil and starch content of soybean are significantly different from that of chickpea. However, there are limited studies on its molecular mechanisms. To address this issue, we conducted integrated transcriptomic and bioinformatics analyses for species-specific genes and acyl-lipid-, starch-, and carbon metabolism-related genes. Among seven expressional patterns of soybean-specific genes, four were highly expressed at the middle- and late oil accumulation stages; these genes significantly enriched fatty acid synthesis and carbon metabolism, and along with common acetyl CoA carboxylase (ACCase) highly expressed at soybean middle seed development stage, common starch-degrading enzyme beta-amylase-5 (BAM5) was highly expressed at soybean early seed development stage and oil synthesis-related genes ACCase, KAS, KAR, ACP, and long-chain acyl-CoA synthetase (LACS) were co-expressed with WRI1, which may result in high seed oil content and low seed starch content in soybean. The common ADP-glucose pyrophosphorylase (AGPase) was highly expressed at chickpea middle seed development stage, along with more starch biosynthesis genes co-expressed with four-transcription-factor homologous genes in chickpea than in soybean, and the common WRI1 was not co-expressed with oil synthesis genes in chickpea, which may result in high seed starch content and low seed oil content in chickpea. The above results may be used to improve chickpea seed oil content in two ways. One is to edit CaWRI1 to co-express with oil synthesis-related genes, which may increase carbon metabolites flowing to oil synthesis, and another is to increase the expression levels of miRNA159 and miRNA319 to inhibit the expression of MYB33, which may downregulate starch synthesis-related genes, making more carbon metabolites flow into oil synthesis. Our study will provide a basis for future breeding efforts to increase the oil content of chickpea seeds.

Biogenic coalbed methane (CBM) is generally believed to be formed by anaerobic bacteria and methanogens, while a few studies took fungi into account. Here, the microflora consisting of fungi and methanogens was enriched from the produced water associated with the Qinshui Basin using anthracite as the only carbon source. The maximum methane yield of 231 μmol/g coal was obtained after 22 days of cultivation under the optimum temperature of 35 °C, pH of 8, salinity of 0–2%, particle size of 0.075–0.150 mm, and the solid–liquid ratio of 1:30. It could remain active even after exposure to air for 24 h. Miseq results showed that the archaea were mainly composed of Methanocella, a hydrogenotrophic methanogen, followed by acetoclastic methanogen Methanosaeta and Methanosarcina, which could use various methanogenic substrates. The fungal communities mainly included Amorphotheca, Alternaria, Aspergillus, and Penicilium, which are all able to degrade complex organics such as aromatics and lignin. After cultivation, the crystal structure of anthracite became looser, as shown by XRD results, which might be due to the swelling effect caused by the destruction of the aromatic ring structure of coal under the function of fungi. The stretching vibration intensity of each functional group in coal decreased with cultivation, as revealed by FTIR. The GC-MS results showed that the concentration of alkanes and alcohols decreased significantly, which are the products of ring-opening of aromatics by fungi. These results suggested that fungi and methanogens in the coalbed also can syntrophically degrade coal effectively, especially for aromatics in coal.

The insect chitinase OfChtI from the agricultural pest Ostrinia furnacalis (Asian corn borer) is a promising target for green insecticide design. OfChtI is a critical chitinolytic enzyme for the cuticular chitin degradation at the stage of molting. In this study, piperine, a natural amide compound isolated from black pepper, Piper nigrum L., was discovered for the first time to have inhibitory activity toward OfChtI. The compound-enzyme interaction was presumed to take place between the piperine benzo[d][1,3] dioxole skeleton and subsite -1 of the substrate-binding pocket of OfChtI. Hence, on the basis of the deduced inhibitory mechanism and crystal structure of the substrate-binding cavity of OfChtI, compounds 5a-f were designed and synthesized by introducing a butenolide scaffold into the lead compound piperine. The enzymatic activity assay indicated that compounds 5a-f (Ki = 1.03-2.04 μM) exhibited approximately 40-80-fold higher inhibitory activity than the lead compound piperine (I) (Ki = 81.45 μM) toward OfChtI. The inhibitory mechanism of the piperonyl butenolide compounds was elucidated by molecular dynamics, which demonstrated that the introduced butenolide skeleton improved the binding affinity to OfChtI. Moreover, the in vivo activity assay indicated that these compounds also displayed moderate insecticidal activity toward O. furnacalis. This work introduces the natural product piperine as a starting point for the development of novel insecticides targeting OfChtI.

Although arsenic at a high concentration imposes strong selective pressure on microbes, various microbes have been found to grow in As-rich environments. So far, little is known about how microbes can sense and move toward arsenate in the environment, and the underlying molecular mechanisms have not been revealed. Here, we report the chemotaxis response toward arsenate (As(V)) by Shewanella putrefaciens CN-32, a model dissimilatory metal-reducing bacterium (DMRB), and elucidate the mechanisms. We find that S. putrefaciens CN-32 exhibits a chemotactic behavior toward As(V) and diverse electron acceptors. To sense As(V), S. putrefaciens CN-32 requires functional arsenate respiratory reductase but does not depend on its metal-reducing-like respiratory pathway. We observe that such a sense is governed by an energy taxis mechanism and mediated by several methyl-accepting chemotaxis proteins (MCPs), rather than a specific MCP. Moreover, we reveal that the chemotactic signal transduction pathway is conserved in Shewanella, and histidine kinase and flagella-mediated motility are essential for taxis toward As(V). This work reverses the conventional view about arsenic as a chemotactic inhibitor to microbes by revealing the positive chemotaxis of Shewanella to As(V).

Carbon-based materials are recognized as promising candidates for pollutant degradation because of their environmental benignity. Massive and cost-effective production and efficient recovery of carbon-based catalysts are crucial to apply this technology. However, various nanostructured carbons with different dimensions are usually utilized as precursors while not considering their complex preparation procedures and the high costs of ingredients. Moreover, catalyst separation and recovery are not given sufficient attention. In this work, a calcium salt-assisted pyrolysis strategy is proposed to tune the catalytic site formation of carbon-based catalysts. Results show that blending equal amounts of Ca

Composite magnetic aluminum hydroxide at iron oxide nanomaterials, Al(OH)3@Fe3O4, with a well-defined core–shell structure, were used as pretreatment adsorbents for the removal of silica in brackis...

In our study, octenyl succinic anhydride (OSA)-modified dextrin was prepared and characterized as a novel emulsifier to improve the stability of emulsion and curcumin encapsulation. Fourier-transform infrared spectroscopy demonstrated the occurrence of esterification between OSA and dextrin (Mw = 1.041 × 104 g/mol). The absolute value of ζ-potential of OSA-dextrin increased (from 25.37 mV to 34.57 mV) with increasing OSA addition (from 0% to 8%), and then kept constant. Confocal laser scanning microscope results showed that the debranching and esterification of starch improved the oil droplets distribution and reduced the droplet size of emulsions. The emulsifying stability of emulsions coated by dextrin was greatly improved with OSA modification. The particle size of emulsion decreased significantly when the addition of OSA increased during storage. OSA-modified dextrin was in a position to increase encapsulation efficiency of curcumin. This research may increase the utilization of emulsions stabilized by OSA dextrin in food industry.

In this study, effect of cross-linking with 4% sodium trimetaphosphate on the structural and adsorptive properties of porous wheat starches was investigated. The results showed that the cross-linked porous starches (CLPS) exhibited lower solubility, swelling power and ordered structure but higher thermal stability compared with the corresponding porous starches (PS). Cross-linking led to the formation of more dense holes on the surfaces of PS, as observed by SEM. XPS results demonstrated that phosphate groups were bound to the OH groups on starches by covalent bonds (COP). Adsorption experiments manifested that the CLPS exhibited higher adsorption capacities for water, oil and methylene blue compared to the corresponding PS. Furthermore, the isothermal data of the CLPS fitted the Langmuir isotherm model well compared to Freundich and Tempkin models, and the adsorption was exothermic and favorable. These results suggest that cross-linking modification can improve the thermal stability and adsorptive properties of PS.

Oridonin could induce NB (neuroblastoma) cells growth inhibition by inducing apoptosis and cell cycle arrest, and the molecular mechanisms behind the effects deserve to be further explored. Here, oridonin was confirmed to cause the reactivation of p53 (cellular tumor antigen p53) to promote the expression of a series of apoptosis‐ and cell cycle arrest‐related proteins for the biological effects. During the process, oridonin relied on the caspase activation to cleave p53‐induced Mdm2 (E3 ubiquitin‐protein ligase Mdm2) to generate Mdm2‐p60. The generation of Mdm2‐p60 stabilized p53, and resulted in p53 accumulation for p53 continuous activation. In our research, it was also found that the reactivation of p53 induced by oridonin was closely related with the generation of ROS (reactive oxygen species). Taken together, these findings explain that oridonin exerts its anticancer activity partially by targeting the Mdm2‐p53 axis in NB cells, which lay an experimental base for future research of exploring the effects and molecular mechanisms of oridonin.

In this study we investigated the antineoplastic effects of Berberine (BBR)-mediated photodynamic therapy (PDT) on HeLa cells and its related mechanisms. The CCK-8 assay and flow cytometry were used to evaluate the proliferation and apoptosis of cells respectively. In addition, changes in protein expression levels were assessed using western blot. BBR at dose of 10 mg/kg was injected intraperitoneally to mice with tumors and PDT treatments were performed 24 hours later. In vivo imaging systems were used to evaluate the fluorescence of BBR. In vitro, PDT significantly enhanced the effects of BBR on inducing cell apoptosis and inhibiting proliferation. The in vivo results showed that the fluorescence intensity in the PDT group was decreased compared with that in the BBR group. Tumor weights and tumor size in the PDT group were less than those in the control group; however, when BBR was applied without PDT, no significant differences were observed between the BBR and control group. The results of western blot showed that PDT enhanced the inhibitory effects of BBR on the mammalian target of rapamycin (mTOR) signaling pathway, that may partly explain the potential underlying mechanisms.

The unique properties of ionic liquids make them attractive for a wide range of industrial applications, which makes it easy to be released into the environment and cause water or soil pollution. Phytoremediation of organic contaminants is a safe and important process for removing persistent pollutants from the environment. However, due to they are very chemically stable and potentially toxic to plants, whether they can be removed, assimilated and metabolized by plants remains unknown during phytoremediation process. In this study, ryegrass, Lolium perenne L., was used for imidazolium ionic liquid (1-butyl-3-methylimidazolium bromide, [C4mim]+) removal from water. The results show that [C4mim]+ could be taken up, accumulated and metabolized by plants in vivo with a high removal efficiency. Most of the [C4mim]+ was accumulated in the root tissue, with the root concentration fraction factors ranging from 4.9 to 51.5. Two hydroxylated metabolites 1-(4-hydroxybutyl)-3-methylimidazolium, and 1-(n-butyl)-3-(hydroxymethyl)-imidazolium, and two secondary metabolites were detected in the ryegrass after [C4mim]+ uptake. The metabolic mechanism was clarified using density functional theory calculations. Furthermore, [C4mim]+ at a high concentration was found to be high toxic to inhibit the growth of ryegrass markedly. In response, some oxidative stress was observed in the metabolic process, as indicated by increasing of catalase, super dismutase and peroxidase activities. Our results suggested that phytoremediation was an efficient technique for ionic liquids treatment from water.

Bisphenol A (BPA) is a semi-persistent environmental endocrine disrupter and widely present in aqueous environments. Electrochemical detection is an effective method to monitor pollutants like BPA in aqueous environments. However, the electrode fouling from anodic polymeric products is one main barrier of electrochemical sensors for their practical applications. In this work, a renewable electrochemical sensor was rationally designed, constructed and tested for efficient BPA detection. The TiO2 anodic material was surface-engineered by inorganic-framework molecular imprinting sites with tailored morphological shape, exposed facet and crystal structure. This electrode could be activated mainly as an electrochemical catalyst and partially as a photochemical catalyst. The developed TiO2-based sensor exhibited a good detection reliability and cyclic stability for determining BPA in water samples, with an electrochemical signal decrease of less than 5.0% in 10-run cyclic tests. By virtue of the bi-functional properties of the tailored TiO2 anodic material, a unique photo-assisted electrochemical sensor was further developed, in which analyte digestion and analytical signal originated mainly from anodic conversion. Such a synergistic digesting mechanism distinguishes it from the reported electro-assisted photochemical TiO2 sensors. Our work provides a robust sensor for monitoring pollutants in aqueous environments and a new opportunity to develop renewable electrode materials with good reusability.

The electrode is the key in electrochemical process for water and wastewater treatment. Many nonstoichiometric metal oxides are active electrode materials but have poor stability under strong anodic polarization due to their susceptible nature of the oxygen vacancies on surface and subsurface as defective reactive sites. In this work, a novel photochemical protecting strategy is proposed to stabilize the defective reactive sites on the TiO2- x surface and subsurface for long-term anodic oxidation of pollutants. With this strategy, a novel photoassisted electrochemical system at low anodic bias is further constructed. Such a system exhibits a high protecting capacity at a low operation cost for electrochemical degradation of bisphenol A (BPA), a typical persistent organic pollutant. Its excellent photochemical protecting capacity is found to be mainly attributed to the mild non-band-gap excitation pathways on the defective TiO2- x electrode under both visible-light irradiation and moderate anodic polarization. Under real sunlight irradiation, a 20 run cyclic test for BPA degradation demonstrates the excellent performance and stability of the constructed system at low bias without significant oxygen evolution. Our work provides a new opportunity to utilize the defective and reactive TiO2- x for efficient, stable, and cost-effective electrochemical water treatment with the aid of its photo- and electrochemical bifunctional properties.

Objectives: We aim to investigate the joint effect of iron (enhanced neonatal iron intake), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and biochanin A (BA, oral administration) and possible mechanisms for action on behavioral and neurochemical indicators in the mice. Methods: Rotarod test, pole test and swim test were used to evaluate animal behavior. The neurochemical analysis was conducted by HPLC-ECD. Oxidative stress was determined in this study. Further mechanism was investigated through in vitro experiments. Results: Iron and MPTP co-administration significantly induced behavioral deficits and decreased striatal dopamine content in the male and female mice. The co-administration of iron and MPTP also significantly induced redox imbalance in the substantia nigra (SN) of mice. Furthermore, BA significantly improved behavioral deficits and increased striatal dopamine content in the mice co-treated with iron and MPTP. BA also significantly improved redox imbalance in the SN of mice co-administered with iron and MPTP. Finally, we showed that iron and 1-Methyl-4-phenylpyridinium (MPP+) co-treatment significantly increased superoxide production in microglial cultures by inducing p38 mitogen-activated protein kinase (MAPK) activation. BA also significantly decreased superoxide production and p38 MAPK phosphorylation in the cultures co-treated with iron and MPP+. Conclusion: Iron and MPTP co-treatment may result in worsened behavioral and neurochemical deficits and aggravated redox imbalance through inducing microglial p38 MAPK activation. BA may improve behavioral and neurochemical deficits and redox imbalance through repressing microglial p38 MAPK activation.

The oil-in-water (O/W) Pickering emulsions stabilized by octenyl succinic anhydride (OSA) modified gliadin nanoparticles (OGNPs), which were prepared through a facile anti-solvent precipitation procedure and ultrasound treatment using gliadin powders, then modified by OSA, have been successfully fabricated. FT-IR result confirmed that the gliadin nanoparticles were modified by OSA. The mean size and three-phase contact angle of OGNPs were larger than those of gliadin nanoparticles, and the zeta potential reversed from positive to negative while the surface and shape of gliadin nanoparticles were destroyed. The effects of OGNPs concentration, OSA content and environment factors viz, pH and ionic strength on the properties of emulsions were investigated. The images, optical microscopy, confocal laser scanning microscopy (CLSM), and droplet size measurement of Pickering emulsions were evaluated. An increase in OGNPs concentration led to a formation of smaller droplets, which increased emulsification efficiency. Similar results were obtained with the addition of OSA from 2% to 10%. Stable emulsions could be developed at the low pH value due to high electrostatic repulsion. Increasing the NaCl concentration destabilized the Pickering emulsions. CLSM showed that OGNPs could be absorbed at the oil-water interface and form a densely packed layer on the surface of spherical oil droplets, which exhibited good stability for 14 days storage. These results suggested that OGNPs may be a promising stabilizer of Pickering emulsions, which may be used as delivery carriers of bioactives.

Photocatalytic catalysis is widely used for pollutant degradation. Since some pollutants with oxidative nature are readily reduced rather than oxidized and reductive reaction caused by photogenerated electrons is limited in the presence of oxygen, photocatalytic reduction process is more applicable for the degradation of pollutants with oxidative nature than oxidation. In this work, a novel bio-photoelectric reductive degradation system (BPRDS), composed of an electrochemically active bacterium Shewanella oneidensis MR-1 and a visible-light photocatalyst Ag3PO4, was established under anaerobic conditions and its photodegradation performance was evaluated through degrading rhodamine B (RhB), a typical organic pollutant. The as-synthesized Ag3PO4 nanoparticles exhibited absorption in the entire visible spectral range of 400–800 nm. RhB could be degraded in BPRDS with visible light irradiation under anaerobic conditions, but not be decomposed in the absence of Shewanella cells. Block of Mtr respiratory pathway, a transmembrane electron transport chain, resulted in a reduction in degradation rate of RHB in BPRDS. Dose of riboflavin also substantially decreased the RhB degradation. These results suggest that the electrons released by Shewanella were involved in the RhB photodegradation, which was achieved via a stepwise N-deethylation process. In BPRDS, RhB was degraded by photoreduction, rather than photooxidation. This work is useful to develop integrated physico-chemical-microbial systems for pollutant degradation, facilitate better understanding about the biophotoelectric reductive degradation mechanisms and beneficial to their applications for environmental remediation. Keywords: Shewanella oneidensis MR-1, Anaerobic degradation, Microbial electron transfer, Nanomaterial, Photoreduction

Biosynthesis offers opportunities for cost-effective and sustainable production of semiconductor quantum dots (QDs), but is currently restricted by poor controllability on the synthesis process, resulting from limited knowledge on the assembly mechanisms and the lack of effective control strategies. In this work, we provide molecular-level insights into the formation mechanism of biogenic QDs (Bio-QDs) and its connection with the cellular substrate metabolism in Escherichia coli. Strengthening the substrate metabolism for producing more reducing power was found to stimulate the production of several reduced thiol-containing proteins (including glutaredoxin and thioredoxin) that play key roles in Bio-QDs assembly. This effectively diverted the transformation route of the selenium (Se) and cadmium (Cd) metabolic from Cd3(PO4)2 formation to CdSxSe1–x QDs assembly, yielding fine-sized (2.0 ± 0.4 nm), high-quality Bio-QDs with quantum yield (5.2%) and fluorescence lifetime (99.19 ns) far exceeding the existing...

Parkinson's disease (PD) is a neurodegenerative disorder, which is characterized by microglia activation and dopaminergic neurons affected by inflammatory processes. Inflammation has been recognized to be necessary for initiation and progress of PD. Emerging evidence indicates that NLRP3 inflammasome complex is involved in the recognition and execution of host inflammatory response. Stress is acknowledged to be a predisposing and precipitating factor in some neurodegenerative diseases. However, it is unknown whether chronic unpredictable mild stress (CUMS) sensitized microglia to pro-inflammatory stimuli. In this study, in vivo experiments are used to evaluate the effects of CUMS on lipopolysaccharide (LPS)-induced microglia activation and NLRP3 inflammasome activation. The results showed that CUMS pretreatment for 14 days significantly aggravated the behavioral dysfunction of PD rats, increased the activation of microglia. Pretreatment with CUMS for 14 days increased the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-a (TNF-a) in the serum, and increased the expression of NLRP-3, ASC, Casepase-1 in the substantia nigra of PD rats. Our data showed that pretreatment with CUMS for 14 days increased the microglia activation and the DA neurons damage, and the mechanisms may be associated with the acceleration of the inflammatory response and activation of NLRP3 inflammasome.

Pyrogenic carbonaceous matter (PCM) catalyzes the transformation of a range of organic pollutants by sulfide in water; however, the mediation mechanisms are not fully understood. In this study, we observed for the first time that the degradation of azo dyes by sulfide initially underwent a lag phase followed by a fast degradation phase. Interestingly, the presence of PCM only reduced the lag phase length of the azo dye decolorization but did not significantly enhance the reaction rate in the fast degradation phase. An analysis of the azo dye reduction and polysulfide formation indicated that PCM facilitated the transformation of sulfide into polysulfides, including disulfide and trisulfide, resulting in fast azo dye reduction. Moreover, the oxygen functional groups of the PCM, especially the quinones, may play an important role in the transformation of sulfide into polysulfides by accelerating the electron transfer. The results of this study provide a better understanding of the PCM-mediated abiotic transformation of organic pollutants by sulfide in anaerobic aqueous environments.

The first highly enantioselective rhodium-catalyzed cross-addition of silylacetylenes to cyclohexadienone-tethered internal alkynes has been achieved via a tandem process: regioselective alkynylation of the internal alkynes and subsequent intramolecular conjugate addition to the cyclohexadienones, affording the cis-hydrobenzofuran frameworks with good yields (up to 88% yield) and excellent enantioselectivities (90%-96% ee). This mild reaction showed perfect atom economy and broad functional group tolerance. Furthermore, a gram-scale experiment and diverse further conversions of the cyclization products were also presented.

Two important fluorophores (quinoline and benzimidazole) have been successfully combined to achieve a novel fluorochrome with desirable fluorescent performance in solution and solid state. This original fluorochrome exhibits not only visual fluorescence quenching toward picric acid (PA) over other nitroaromatics and common interferents, but also ppb-level (4.86 ppb) of detection limit in semi-aqueous solution. In addition, the other sensing properties such as rapid response (second-level), good environmental compatibility (pH tolerability) and sensitivity are also evidentially revealed. The dominant quenching mechanism involves a synergistic effect of inner filter effect and photoinduced electron transfer (PET), which is fully supported by spectral analysis, 1H NMR assay, morphological studies, lifetime experiments and theoretical calculation. Noteworthily, the fluorochrome can be readily used in real water samples for quantitative determination of PA and processed as fluorescent paper or thin layer chromatography (TLC) plate for naked-eye detection, which enable itself to be functionalized as applicable PA sensor.

Antagonism between heavy metal and selenium (Se) could significantly affect their biotoxicity, but little is known about the mechanisms underlying such microbial-mediated antagonistic processes as well as the formed products. In this work, we examined the cadmium (Cd)-Se interactions and their fates in Caenorhabditis elegans through in vivo and in vitro analysis and elucidated the machinery of Se-stimulated Cd detoxification. Although the Se introduction induced up to 3-fold higher bioaccumulation of Cd in C. elegans than the Cd-only group, the nematode viability remained at a similar level to the Cd-only group. The relatively lower level of reactive oxygen species in the Se & Cd group confirms a significantly enhanced Cd detoxification by Se. The Cd-Se interaction, mediated by multiple thiols, including glutathione and phytochelatin, resulted in the formation of less toxic cadmium selenide (CdSe)/cadmium sulfide (CdS) nanoparticles. The CdSe/CdS nanoparticles were mainly distributed in the pharynx and intestine of the nematodes, and continuously excreted from the body, which also benefitted the C. elegans survival. Our findings shed new light on the microbial-mediated Cd-Se interactions and may facilitate an improved understanding and control of Cd biotoxicity in complicated coexposure environments.

In the absence of metal catalysis and an additive, with ethyl acetate as a solvent at 95 °C under air atmosphere for 2 h, an eco-friendly and practical protocol for the synthesis of 4-ethylpiperazine derivatives through a 3,4-dihalo-2(5H)-furanone initiated ring-opening reaction of DABCO is developed. Satisfactory reactivity with moderate to excellent yields and 100% atom economy are observed. This potential bioactive synthon promoted ring-opening reaction is not only important for the development of new drugs, but also suitable for other cyclic tertiary amines (e.g. 1-methylpyrrolidine) with good yields. In addition, due to the newly generated alkyl halide structural unit in the product, its application in one-pot two-step reactions with different kinds of nucleophilic reagents can be achieved as designed.

Three novel bisbenzimidazole derivatives have been synthesized and developed as dual-functional fluorescent sensors for the rapid and highly selective detection of Ag+ and Fe3+ ions in semi-aqueous medium with distinct spectral response for the first time. The absorption intensity is drastically decreased after the addition of Ag+. Contrarily, it is markedly increased upon the addition of Fe3+. And there is a good linear relation at low concentration of both Ag+ and Fe3+, which provides a quantitative method for their detection. Similarly, the sensors show a distinct fluorescence response towards Ag+ and Fe3+ with a different fluorescence color change under UV light. In addition, no significant changes and interference can be observed with other metal ions. The sensing mechanism studies confirm that the N atom in CN of benzimidazole ring of sensor 4a may bind with Ag+ or Fe3+ ion to form metal complex. And there is only a static quenching process for the 4-Ag+ complex system, but both dynamic and static quenching processes occur in the 4-Fe3+ complex system. Moreover, sensors 4 can steadily work in solution with a wide range of pH 4-13 and rapidly respond to Ag+ and Fe3+ with a response time of 10 s. Finally, the sensors have been successfully applied to the visual detection of Ag+ and Fe3+ not only in solution, but also in test paper.

Visible-light-driven photocatalysis has been widely employed as an efficient and environment-friendly technology for organic pollutants removal from wastewaters. Herein, a novel approach of BiVO4-catalyzed sulfite under visible light irradiation (BiVO4/sulfite/vis) was established to achieve the model contaminant methyl orange (MO) removal. About 92.06% of MO could be rapidly degraded within 50 min in this new catalytic system and the reaction rate was close to 105.29-fold as high as that of BiVO4/vis system. The effects of sulfite amount, catalysis dosage, MO concentration, inorganic anions and natural organic matters (NOMs) were deeply investigated and the correspondent mechanisms were also discussed. Interestingly, the coexisting Cr(VI) at certain concentration would accelerate MO removal and further demonstrated by phenol and atrazine degradation through the Cr(VI) + organic pollutants combined pollution system. The presence of HA in BiVO4/sulfite/vis also exhibited positive effects on the degradation of organic pollutants, attributable to more OH species generation. Three-dimensional excitation-emission matrix fluorescence spectra (3D EEMs) and liquid chromatography-mass spectrometer (LC-MS) were implemented to explore MO degradation pathway. The sulfite (SO3 −) generation was confirmed by active species trapping experiments and electron spin resonance (ESR), and N2 purging reaction was also carried out to exclude the oxidative species of SO3 −. The photoinduced holes played a direct role in the SO3 − generation and the OH radical also contributed. This study provides new thoughts to improve the photodegradation of multiple organic pollutants by the introducing of sulfite or sulfite/Cr(VI).

Here, we show that berberine (BBR) nanoparticles (BBRNPs, ∼300 nm hydrodynamic diameter) are a promising sonosensitizer for cancer sonodynamic therapy (SDT). HeLa cells were cultured for in vitro investigation, and a HeLa xenograft tumor model was established with BALB/c nude mice (∼20 g, female) for in vivo study. Significant effects of BBRNP-mediated SDT were observed in both in vitro and in vivo experiments. Cell counting kit-8 (CCK-8) cell proliferation and cytotoxicity assays were performed to confirm if BBRNPs-SDT has cytotoxicity against HeLa cells in vitro. The mechanism for inhibition of tumor proliferation by BBRNPs-SDT was investigated via flow cytometry, photoluminescence spectroscopy, dynamic light scattering, scanning electron microscopy, ultrasonic contrast imaging, tumour pathological analysis, western blot and anatomical analysis. We identified two ongoing assumptive mechanisms. One is due to the tumor angioembolism effect, which blocks oxygen and nutrient supply in situ, leading to early-stage HeLa apoptosis. The other domino effect is due to ultrasonic energy-activated BBRNP cavitation and reactive oxygen species release, which leads to tumor vascular injury and finally induces HeLa apoptosis, resulting in tumour shrinkage. Both pathways synergistically helped with HeLa xenograft tumor supression. In conclusion, we posit that BBRNPs are a promising agent for tumor SDT.

Coastal wetlands are widely recognized as atmospheric methane sources. However, recent field studies suggest that some coastal wetlands could also act as methane sinks, but the mechanism is not yet clear. Here, we investigated methane oxidation with different electron acceptors (i.e., oxygen, nitrate/nitrite, sulfate, Fe(III) and Mn(IV)) in four coastal wetlands in China using a combination of molecular biology methods and isotopic tracing technologies. The geochemical profiles and in situ Gibbs free energies suggest that there was significant nitrite-dependent anaerobic oxidation of methane (nitrite-AOM) in the sub-surface sediments; this was subsequently experimentally verified by both the microbial abundance and activity. Remarkably, the methanotrophic communities seemed to exist in the sediments as layered structures, and the surface aerobic methane-oxidizing bacteria were able to take up atmospheric methane at a rate of 0.10–0.18 nmol CH4 day−1 cm−2, while most, if not all, sedimentary methane was being completely consumed by anaerobic methanotrophs (23–58% by methane oxidizers in phylum NC10). These results suggest that coastal methane sinks might be governed by diverse microbial communities where NC10 methane oxidizers contributed significantly. This finding helps to better understand and predict the coastal methane cycle and reduce uncertainties in the estimations of the global methane flux.

An efficient approach for C–N bond construction by the coupling reaction of arylsulfonyl hydrazides and Csp2–X compounds is described for the first time with good yields at room temperature. The reaction promoted by the simple base DMAP displays excellent regioselectivity as well as high functional group tolerance with 41 examples. Even for inactive Csp2–Cl compounds, the metal-free transformation also affords a satisfactory yield after prolonging the reaction time, which is comparable to that of the corresponding Csp2–Br compound. The good effect of DMAP and its action mechanism are confirmed by the competitive experiments of reactivity between Cl-substituted and Br-substituted substrates and the single-crystal X-ray analysis of the key intermediate quaternary ammonium salt. Importantly, the application of this method for a gram-scale (even over 10 g) preparation can be accomplished.

Berberine (BBR) is a plant secondary metabolite that has been used in photodynamic therapy (PDT) in the last few decades. The present review aimed to discuss the research progress of BBR-mediated photodynamic actions. The following key words were searched in several databases: 'Berberine' combined with 'photodynamic therapy', 'sonodynamic therapy (SDT)', 'ultraviolet', 'reactive oxygen' and 'singlet oxygen'. The results demonstrated that both type I and type II reactions participated in the photodynamic progression of BBR derivatives. In addition, the photochemical characteristics of BBR derivatives were affected by the polarity, pH and O2 content of solvents. DNA binding increases the lifespan of the photoexcited BBR state and generation of singlet oxygen (1O2). The chemical properties of substituents in different positions of the BBR skeleton are pivotal for its photochemical properties, particularly the methylenedioxy group at the C-2 and C-3 positions. BBR is a promising agent for mediating both PDT- and SDT-treated diseases, particularly in tumors. However, further studies are required to validate their biological effects. In addition, the molecular mechanisms underlying the antitumor effects of BBR-PDT remain unclear and warrant further investigation. The structural modification and targeted delivery of BBR have made it possible to broaden its applications; however, experimental verification is required. Overall, BBR acts as a sensitizer for PDT and has promising development prospects.

A series of pleuromutilin derivatives with 1,2,4-triazole-3-substituted Schiff base structure were designed and synthesized under mild conditions. The in vitro antibacterial activities of the synthesized derivatives against 4 strains of Staphylococcus aureus (MRSA ATCC 43300, S.aureus ATCC 29213, S.aureus 144 and S.aureus AD3) and 1 strain of E. coli (ATCC 25922) were evaluated by the broth dilution method. Among these derivatives, compound 60 exhibited superior in vitro antibacterial effect against MRSA (MIC = 0.25 μg/mL) than tiamulin (MIC = 0.5 μg/mL), and compound 60 (−2.28 log10 CFU/mL) also displayed superior in vivo antibacterial efficacy than tiamulin (−1.40 log10 CFU/mL) in reducing MRSA load in the mouse thigh infection model. The time-kill study and the post-antibiotic effect study indicated that compound 60 showed a faster bactericidal kinetic and longer PAE time (exposure to 2 × MIC and 4 × MIC for 2 h, the PAE was 4.06 and 4.27 h) against MRSA compared with tiamulin (exposure to 2 × MIC and 4 × MIC for 2 h, the PAE was 1.72 and 2.14 h). Meanwhile, most of these compounds had no significant inhibitory effect on RAW 264.7 cells and HepG2 cells at the concentration of 4 μg/mL. Additionally, the development of resistance study showed that MRSA did not easily develop resistance against compound 60 compared with tiamulin after induction for 8 passages.