Search

In this work, Ag/Bi5O7I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange (MO) degradation. Bi5O7I was synthesized via a hydrothermal-calcination method and shows nanorods morphology. Ag nanoparticles (NPs) were photo deposited on the Bi5O7I nanorods as electron trappers to improve the spatial separation of charge carriers, which was confirmed via XPS, TEM, and electronic chemical analyses. The catalytic test indicates that Bi5O7I presents the piezoelectric-like behavior, while the loading of Ag NPs can strengthen the character. Under ultrasonic vibration, the optimal Ag/Bi5O7I presents high efficiency in MO degradation. The degradation rate is determined to be 0.033 min−1, which is 4.7 folds faster than that of Bi5O7I. The Ag/Bi5O7I also presents a high performance in piezocatalytic N2 fixation. The piezocatalytic NH3 generation rate reaches 65.4 μmol L−1 g−1 h−1 with water as a hole scavenger. The addition of methanol can hasten the piezoelectric catalytic reaction. Interestingly, when ultrasonic vibration and light irradiation simultaneously act on the Ag/Bi5O7I catalyst, higher performance in NH3 generation and MO degradation is observed. However, due to the weak adhesion of Ag NPs, some Ag NPs would fall off from the Bi5O7I surface under long-term ultrasonic vibration, which would greatly reduce the piezoelectric catalytic performance. This result indicates that a strong binding force is required when preparing the piezoelectric composite catalyst. The current work provides new insights for the development of highly efficient catalysts that can use multiple energies.

This work synthesized a novel CuS/KTa0.75Nb0.25O3 (KTN) heterojunction composite and firstly applied it in photocatalytic and piezocatalytic reduction of N2 to NH3. XRD, Raman, XPS, SEM, and TEM analyses indicate that CuS nanoparticles closely adhered to the surface of KTN nanorods, which facilitates the migration of electrons between the two semiconductors. Mott-Schottky and valence band XPS analysis shows that KNbO3 shows a higher conduction band than CuS, indicating that CuS mainly acts as electron trappers to capture the photogenerated electrons from KTN. Because of the great enhanced spatial separation of photogenerated charge carriers, the CuS/KTN presents much higher performance than pure KNT, which is further confirmed by 1H NMR analysis of the reaction solution. An interesting finding is that synthesized CuS/KTN not only performs well under light irradiation but also can work in an ultrasonic bath, indicating its great potential in photo/piezocatalytic conversion of N2 to NH3. The optimal 10 %CuS/KTN shows an NH3 production rate of 36.2 μmol L−1 g−1 h−1 under ultrasonic vibration, which reaches 7.4 times that of KTN. The electrons generated by KTN through the piezoelectric effect can be captured by CuS, which endows the electrons a longer life to participate in the reaction, thereby improving the catalytic reaction performance.

Background Epigenetic mark such as DNA methylation plays pivotal roles in regulating ripening of both climacteric and non-climacteric fruits. However, it remains unclear whether mRNA m6A methylation, which has been shown to regulate ripening of the tomato, a typical climacteric fruit, is functionally conserved for ripening control among different types of fruits. Results Here we show that m6A methylation displays a dramatic change at ripening onset of strawberry, a classical non-climacteric fruit. The m6A modification in coding sequence (CDS) regions appears to be ripening-specific and tends to stabilize the mRNAs, whereas m6A around the stop codons and within the 3′ untranslated regions is generally negatively correlated with the abundance of associated mRNAs. We identified thousands of transcripts with m6A hypermethylation in the CDS regions, including those of NCED5, ABAR, and AREB1 in the abscisic acid (ABA) biosynthesis and signaling pathway. We demonstrate that the methyltransferases MTA and MTB are indispensable for normal ripening of strawberry fruit, and MTA-mediated m6A modification promotes mRNA stability of NCED5 and AREB1, while facilitating translation of ABAR. Conclusion Our findings uncover that m6A methylation regulates ripening of the non-climacteric strawberry fruit by targeting the ABA pathway, which is distinct from that in the climacteric tomato fruit.

As a promising anode for potassium-ion batteries (PIBs), graphite has drawn great attention due to easy availability, low cost and formation of potassium-based intercalation compound. However, poor cyclic and rate performances due to severe structural degradation limit the practical application of graphite anode. Herein, a low cost mildly-expanded graphite (MEG) with adjustable interlayer lattice distance is synthesized through a wet chemical oxidation route. As anode for PIBs, the MEG exhibited stable intercalation/deintercalation plateaus, outstanding cyclic stability and rate performance. By optimizing the mass ratio between graphite and potassium permanganate oxidant, the MEG anode retaining long-range-ordered domains of graphite delivers a capacity of 88 mAh/g at 1500 mA/g and a capacity retention of 72.3% after 200 cycles at 100 mA/g. The potassium ion full cell assembled with MEGs anode exhibites high energy density and outstanding cyclic stability. Our results demonstrate a promising graphite-based anode for PIBs and provide guidance for the designing of novel carbonic electrodes for PIBs.

The discontinuous crack surface in a rock affects the stability of the whole rock system. The experiments in this paper were carried out by prefabricating rock-like specimens with different types of flaws, then the specimens were tested under uniaxial compression. Moreover, based on the theory of particle flow, PFC2D software was used for numerical simulation, and the comparative analysis of the experimental and simulative results was carried out to obtain the crack initiation sequence, propagation phenomenon, and failure mode of rock specimens with different flaw types. The results indicated that the wing crack started at the tip of flaw and the form of crack assumed split failure, followed by shear failure caused by the secondary crack. The tensile failure degree decreases and the influence of shear failure increases with the increase of flaw angle. The wing crack and secondary initiation stress value is 35%–55% and 85%–95% of the peak stress value. Crack coalescence appeared in adjacent flaws of rock-like specimens with multiple parallel single flaws, single-cross flaws and double-cross flaws, and the coalescence phenomenon always occurs when the stress peak value is reached. With the number of flaws increasing, the splitting failure of rock-like specimens became more and more serious, the splitting failure of double cross-flaw specimen is the most serious. As for the specimen with single-cross flaw, the wing crack would be produced at the tip of the flaw with larger obliquity. The results of this paper may offer certain reference value for the study on the mechanism of rock crack.

Based on the comprehensive evaluation system of agricultural green development index (AGDI), this paper uses entropy weight method and linear weighted sum method to measure the agricultural green development level of 31 provinces in China from 2013 to 2018. We then incorporate spatial correlation into the traditional convergence test model, study the spatial convergence of AGDI, and explore the reasons for regional differences in AGDI. The results show that the level of AGDI in China showed an overall growth trend during the sample survey period, but there were significant differences in the rate of AGDI among different regions, mainly manifested as "eastern > western > central." The AGDI shows a significant positive spatial correlation on the whole, and its overall spatial distribution is characterized by high-high agglomeration and low-low agglomeration. The provinces with higher and lower level of AGDI still maintain the original relatively concentrated distribution in geographical space. On this basis, the study examines the regional differences of AGDI and its evolution by Dagum Gini coefficient decomposition and spatial convergence. The results showed that the overall difference of AGDI showed a fluctuating downward trend. The intra-regional difference of AGDI in the western region was the largest, and that in the eastern region was the smallest. The contribution rate of intensity of transvariation among regions was the main source of the relative difference of AGDI. Meanwhile, the AGDI of the overall, eastern, central, and western regions present significant σ convergence and conditional β convergence. Except for the central region, the overall, eastern, and western regions present significant absolute β convergence. The low-level areas of AGDI have significant "catch-up effect" on the areas with high-level AGDI. Based on the above results, this paper also puts forward some policy suggestions from the perspective of cross-regional collaborative governance to improve China's agricultural green development mode and narrow the regional differences of China's agricultural green development.

A novel Bi2S3/KTa0.75Nb0.25O3 (KTN) heterojunction nanocomposite was prepared through a simple two-step hydrothermal method and primarily applied in photocatalytic and piezocatalytic N2 fixation. Bi2S3 closely adhered to the surface of KTN nanorods and mainly acted as electron trappers to capture the photogenerated electrons in the composite, which promotes the spatial separation of photogenerated charge carriers greatly. Thus, Bi2S3/KTN exhibited good performance in photocatalytic N2 reduction to NH3. Besides the high photocatalytic performance in photocatalysis, Bi2S3/KTN also performed well in piezocatalytic N2 fixation. The remarkable piezoelectric properties of KTN are a key factor. The added Bi2S3 can extend the lifetime of the negative charges generated by the piezoelectric effect, thereby improving the catalytic reaction performance. This work demonstrates the great potential of Bi2S3/KTN in photo/piezocatalytic N2 fixation.

Summary To enrich our knowledge about gene network of fatty acid biosynthesis in cottonseed, we conducted comparative transcriptome to reveal the differences in gene expression between Gossypium hirsutum and Gossypium barbadense during cottonseed development. The prolonged expression period and increased expression abundance of oil‐related genes are the main reasons for producing high seed oil content (SOC) in G. barbadense, which manifested as the bias of homeologous gene expression in Dt‐subgenome after 25 day postanthesis (DPA). The dynamic expression profile showed that SAD6 and FATA are more important for oil biosynthesis in G. barbadense than that in G. hirsutum. Three key transcription factors, WRI1, NF‐YB6 and DPBF2, showed their elite roles in regulating seed oil in cotton. We observed that sequence variations in the promoter region of BCCP2 genes might contribute to its divergence in expression level between the two species. Based on the quantitative trait loci (QTL) information of the seed oil content and utilizing additional G. barbadense introgression lines (ILs), we propose 21 candidate genes on the basis of their differential expression level, of which the GbSWEET and the GbACBP6 showed the potential functional to improve the oil content. Taken together, studying the different expression of oil‐related genes and their genetic regulation mechanisms between G. hirsutum and G. barbadense provide new insights to understanding the mechanism of fatty acid biosynthesis network and fatty acid genetic improving breeding in cotton.

Chiral emissive liquid crystals (N*-LCs) have been proved to greatly amplify the circularly polarized luminescence (CPL) signals due to highly regular spiral arrangement of dyes in a well-organized liquid crystals system. Normally, CPL materials with a high luminescence dissymmetry factor (glum) and quantum yield (QY) can meet the real application requirement. Here, four chiral aggregate-induced emission (AIE) active donors (Guests A1-A4: R-C2, R-C4, R-C6, R-C8, chiral dopant, and energy donor) and achiral AIE-active acceptors (Guest B: PBCy, CPL emitter) were doped into the commercial nematic liquid crystals E7 (N-LCs, Host) to form CPL-active ternary chiral emissive N-LCs (T-N*-LCs), respectively. This kind of T-N*-LCs could emit strong red CPL with QY = 16.56% and glum up to 1.51 through intermolecular energy transfer and chirality induction from the supramolecular self-assembly of T-N*-LCs. This work provides the effective strategy for the development of high glum CPL materials.

Chemodynamic therapy (CDT) refers to generating hydroxyl radical ( OH) in tumor sites via hydrogen peroxide (H2O2) catalyzed by transition metal ions in cancer cells under acidic environment. However, H2O2 content is not enough for effective CDT, although H2O2 content in cancer cells is higher than that of normal cells. Herein, we synthesized DOX@BSA-Cu NPs (nanoparticles) for effective CDT by providing enhanced content of H2O2 in cancer cells. The results proved Cu2+ in NPs could be reduced to Cu+ by glutathione (GSH) and effectively converted H2O2 to OH. Moreover, the loaded low-dose doxorubicin (DOX) in the NPs could improve the content of H2O2 and resulted in more efficient generation of OH in cancer cells. Thus DOX@BSA-Cu NPs exhibited higher cytotoxicity to cancer cells. This research may provide new ideas for the further studies on more effective Cu(II)-based CDT nanoagents.

A solar-powered biomass steam gasification system was developed, in which heat transfer model, flow model and chemical model were constructed to predict the distributions of temperature, pressure, mole fraction of syngas, and solar incident flux. Several key parameters of gasifier were designed to ensure the fluidization stability. Based on the model validation, gasifier performance simulations in the design working conditions were obtained. The effects of the key variable parameters, including the rim angle of the dish collector, steam-to-biomass mass flow ratio, biomass feeding rate and the solar irradiance in the different operation working conditions on the composition of syngas, lower heating value, and efficiencies were investigated. The results reveal that the coupled system implements the best gasification performance in the design conditions which the rim angle, steam-to-biomass mass flow ratio, and biomass feeding rate are set at 60°, 0.4, and 2.5 g/min, while the LHV, carbon conversion, and gasification energy efficiencies are 11.51 MJ/m3, 78.17%, and 93.01%, respectively. The overall energy efficiency considering solar energy is 30.79%.

Nowadays, alkali metal-oxygen batteries such as Li-, Na-, and K-O2 batteries have been investigated extensively because of their ultrahigh energy density. However, the oxygen crossover of oxygen ba...

In this study, the predictability of the Madden–Julian Oscillation (MJO) is investigated using the coupled Community Earth System Model (CESM) and the climatically relevant singular vector (CSV) method. The CSV method is an ensemble-based strategy to calculate the optimal growth of the initial error on the climate scale. We focus on the CSV analysis of MJO initialized at phase II, facilitating the investigation of the effect of the initial errors of the sea surface temperature (SST) in the Indian Ocean on it. Six different MJO events are chosen as the study cases to ensure the robustness of the results. The results indicate that for all the study cases, the optimal perturbation structure of the SST, denoted by the leading mode of the singular vectors (SVs), is a meridional dipole-like pattern between the Bay of Bengal and the southern central Indian Ocean. The MJO signal tends to be more converged and significant in the Eastern Hemisphere while the model is perturbed by leading SV. The moist static energy analysis results indicate that the eastward propagation is much more evident in the terms of vertical advection and radiation flux than others. Therefore, the SV perturbation can strengthen and converge the MJO signal mostly by increasing the vertical advection of the moist static energy. Further, the sensitivity studies indicate that the structure of the leading SV is not sensitive to the initial states, which suggests that we might not need to calculate SVs for each initial time in constructing the ensemble prediction, significantly saving computational time in the operational forecast systems.

Potassium-ion battery (KIBs) as an economical and high energy candidate for grid-scale applications has drawn significant attention recently. Given the reversible formation of K-graphite intercalation compound, mass production and low price, the graphite is one of the most promising anode materials for KIBs. However, the issue on the fast capacity fading seriously limits the real application of graphite. The formation and stability of solid electrolyte interphase (SEI) at electrode/electrolyte interfaces during the potassiation/depotassiation or plating/striping processes is closely correlated to the above issue. Herein, by employing typical K/graphite batteries the effect of SEI on the capacity fading were systematically investigated in two electrolyte systems (i.e., ester (EC/DEC) and ether (DEGDME) based electrolytes). The decomposition of EC/DEC electrolyte led to the continuous thickening of SEI on K anode, which should be mainly responsible for the fast capacity decay of K/graphite batteries in EC/DEC electrolyte. The gradual distortion of graphite structure is the secondary cause. By comparison, the more stable DEGDME electrolyte and slight graphitic structure degradation lead to better cyclic stability. Additionally, the components of SEI on graphite anodes in full-cells are basically consistent with those in half-cells. In a word, our work provides a guidance for understanding the scientific issues on how the formation and the stability of SEI influences on the capacity decay in KIBs with graphite anodes.

Numerous works have indicated that westerly wind bursts (WWBs) have a significant contribution to the development of El Niño events. However, the simulation of WWBs commonly suffers from large biases in the current generation of coupled general circulation models (CGCMs), limiting our ability to predict El Niño events. In this study, we introduce a WWBs parameterization scheme into the global coupled Community Earth System Model (CESM) to improve the representation of WWBs and to study the impacts of WWBs on El Niño-Southern Oscillation (ENSO) characteristics. It is found that CESM with the WWBs parameterization scheme can generate more realistic characteristics of WWBs, in particular their location and seasonal variation of occurrence. With the parameterized WWBs, the skewness of the Niño 3 index is increased, in better agreement with observation. Eastern Pacific El Niño and central Pacific El Niño events could be successfully reproduced in the model run with WWBs parameterization. Further diagnoses show that the enhanced horizontal advection in the central Pacific and vertical advection in the eastern Pacific, both of which are triggered by WWBs, are crucial factors responsible for the improvements in ENSO simulation. Clearly, WWBs have important effects on ENSO asymmetry and ENSO diversity.

Potassium-ion batteries (PIBs) are considered to be potential alternatives to the conventional lithium-ion batteries (LIBs) due to the similar working mechanism and abundant potassium (K) resource. However, it still remains challenging to directly apply commercial graphite anodes for PIBs owing to the large K ions, which may impede the electrochemical intercalation of K ions into the graphite interlayer and result in a poor cyclic stability and rate capability. Reduced graphene oxide (rGO) has shown remarkable electrochemical performance as an anode material for PIBs due to the fact that rGO possesses more active sites with an enlarged interlayer distance. Understanding the microstructure of rGO is crucial for optimizing its K-ion storage capabilities. Herein, it is revealed that the K-ion storage behavior of rGO is strongly dependent on the thermal treatment temperature on account of the difference in microstructure. rGO graphitized at 2500 °C exhibits a superior long-term cyclic stability for 2500 cycles due to the expanded interlayer distance and the unique graphite-like structure in a long range, enabling it to endure the huge volume change during uninterrupted K-ion intercalation/deintercalation processes.

Botrytis cinerea is an economically devastating necrotrophic fungus with many host species, and the fungicides commonly used to control it cause serious food and environmental safety problems. It is therefore urgent to develop alternative control measures for these pathogen fungicides. The glucose oxidase enzyme (GOX) is an oxido-reductase that catalyzes the oxidation of glucose to hydrogen peroxide (H2O2) and gluconic acid. GOX has been widely used as a food additive because of its safety and oxidation properties, but little is known about its antifungal effects against B. cinerea, and there have been no reports of its application for pathogen control of postharvest fruit. Here, we examined the antimicrobial activity of GOX against B. cinerea spores and developed a GOX-glucose (10 g/L) system that can significantly restrict fungal growth on postharvest strawberry fruit. A variety of optical and electron microscopy investigations revealed that GOX inhibits B. cinerea growth by altering the morphology of mycelial membranes, among other deleterious effects. Biochemical analyses supported the observation that GOX-mediated growth inhibitory effects result from its competition of carbon and enzymatic production of H2O2 and from the acidifying influence of gluconic acid. Our demonstration of this GOX-glucose system as a control agent to protect postharvest fruit opens the door for the application of this technology to other crops and for further investigation of the mechanisms that can interrupt B. cinerea growth.

Formaldehyde (CH2O) is the most common volatile organic pollutant in the indoor environment, which can directly cause respiratory system diseases of humans. As a new type of material, graphene-based single atom adsorbent has the advantages of large specific surface and high adsorption activity, which can provide a new direction for formaldehyde removal. In this paper, the adsorption characteristics of formaldehyde on graphene-based single atom adsorbents were investigated through density functional theory (DFT) calculations. According to the analysis of geometric structure, electron transfer and density of states (DOS), the adsorption of formaldehyde belongs to a stable chemisorption and the largest adsorption energy of formaldehyde is −2.27 eV, which is a combined action of electron transfer and hybridization effect. Formaldehyde will be preferentially adsorbed on single atom adsorbent in side-on model. The effect of N doping and desorption temperature were studied through searching for linear relationship and Gibbs free energy calculation, respectively. Doping N atoms into graphene plane can significantly improve the adsorption strength of formaldehyde through modulating the charge of metal atoms. The charge of metal atoms can be an efficient descriptor for adsorption energy of formaldehyde. CH2O plays a dominant role in competitive adsorption between O2, N2 and CH2O. We expect that this theoretical study can lay a foundation for the experimental investigations.

FeCrAl alloys are promising accident-tolerant fuel (ATF) cladding materials for applications in light water reactors (LWRs). Despite the excellent mechanical and antioxidation properties, this series of iron-based alloys has poor hydrogen embrittlement (HE) resistance due to the strong hydrogen uptaking ability. The hydrogen embrittlement effect can cause the degradation and premature failure of the material, and this effect can be enhanced by the high-temperature/high-pressure/high-irradiation environment in reactors. So, the potential danger should be taken seriously. In this paper, we have studied the hydrogen atom and molecule adsorptions on both Fe (100) and FeCrAl (100) surfaces to discover how the hydrogen atom and molecule (H/H2) interact with the Fe and FeCrAl (100) surface in the first place. The results show that there are strong element effects on the FeCrAl surface. The Al atom itself has no interaction with hydrogen. When the Al atom is beside the Fe atom, this Fe atom has a slightly lower interaction with hydrogen. However, the Al atom beside the Cr atom will enhance the hydrogen interaction with this Cr atom. On the other hand, when the Cr atom is beside the Fe atom, these two atoms (Fe–Cr bridge site) can reduce the interactions with H. In addition, when two Cr and two Fe atoms together make a four-fold site (FF site), the two Cr atoms can increase the interaction of the two Fe atoms with H. The element effects discovered can be a good guide for making hydrogen prevention coatings.

Obesity has been followed with interest as a risk factor for COVID-19, with triglycerides as one of four common criteria used to define obesity, which have been used to study the mechanism of obesity. In this study, we showed that angiotensin-converting enzyme-2 (ACE2) is widely expressed in the mouse body, including the kidney, spleen, brain, heart, lung, liver, and testis, and that ACE2 levels increased after a high-fat diet. The ACE2 levels were recorded at 0 days, 3 days, 7 days, and 14 days after a high-fat diet, and they increased at 14 days after high-fat diet initiation. In addition, triglyceride levels were also significantly increased at 14 days after high-fat diet initiation, but body weight was not changed. Furthermore, we examined the ACE2 levels in Calu3 cells (a lung cancer cell line) after triglyceride treatment, and the results indicated that ACE2 levels were increased at 25 μM and reached their peak at 200 μM. Finally, we found that the mRNA level of mthfd1 was significantly increased in the high-fat diet group. Given these findings, we hypothesize that triglycerides can regulate the expression of ACE2 and Mthfd1.

Ceramic material is one of the essential materials used in reactors. Beryllium oxide ceramics have good high-temperature radiation stability, high density, high strength, and thermal conductivity at high temperatures, and the price of beryllium oxide is relatively moderate. This makes it more suitable for use as a reflector, moderator, and dispersion phase fuel matrix in a reactor. In recent years, beryllium oxide has attracted widespread attention due to its high hardness, high resistivity, high thermal conductivity, high melting point, and high radiation resistance. Because of its excellent mechanical properties, beryllium oxide materials also have a long history in the field of nuclear energy. Reactor extreme environments have become a significant challenge for optimizing reactor operation and safety performance. The utilization of beryllium oxide can significantly alleviate extreme reactor environments. According to research, the coupling of beryllium oxide material can effectively improve nuclear fuels' thermal conductivity, such as uranium dioxide. Beryllium oxide also has good radiation resistance and neutron scattering properties, which increases its applications in nuclear energy. The article comprehensively reviews the BeO utilization approaches in reactors to improve extreme reactor environments for current reactor operation and future reactor design optimization.

To better understand the source–sink flow and its relationships with zinc (Zn) and other nutrients in wheat (Triticum aestivum L.) plants for biofortification and improving grain nutritional quality, the effects of reducing the photoassimilate source (through the flag leaf removal and spike shading) or sink (through the removal of all spikelets from one side of the spike, i.e., 50% spikelets removal) in the field of the accumulation of Zn and other nutrients in grains of two wheat cultivars (Jimai 22 and Jimai 44) were investigated at two soil Zn application levels. The kernel number per spike (KNPS), single panicle weight (SPW), thousand kernel weight (TKW), total grain weight (TGW) sampled, concentrations and yields of various nutrient elements including Zn, iron (Fe), manganese (Mn), copper (Cu), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), phytate phosphorus (phytate-P), phytic acid (PA) and phytohormones (ABA: abscisic acid, and the ethylene precursor ACC: 1-aminocylopropane-1-carboxylic acid), and carbon/N ratios were determined. Soil Zn application significantly increased the concentrations of grain Zn, N and K. Cultivars showing higher grain yields had lower grain protein and micronutrient nutritional quality. SPW, KNPS, TKW (with the exception of TKW in the removal of half of the spikelets), TGW, and nutrient yields in wheat grains were most severely reduced by half spikelet removal, secondly by spike shading, and slightly by flag leaf removal. Grain concentrations of Zn, N and Mg consistently showed negative correlations with SPW, KNPS and TGW, but positive correlations with TKW. There were general positive correlations among grain concentrations of Zn, Fe, Mn, Cu, N and Mg, and the bioavailability of Zn and Fe (estimated by molar ratios of PA/Zn, PA/Fe, PA × Ca/Zn, or PA × Ca/Fe). Although Zn and Fe concentrations were increased and Ca was decreased in treatments of half spikelet removal and spike shading, the treatments simultaneously increased PA and limited the increase in bioavailability of Zn and Fe. In general, different nutrient elements interact with each other and are affected to different degrees by source–sink manipulation. Elevated endogenous ABA levels and ABA/ACC ratios were associated with increased TKW and grain-filling of Zn, Mn, Ca and Mg, and inhibited K in wheat grains. However, the effects of ACC were diametrically opposite. These results provide a basis for wheat grain biofortification to alleviate human malnutrition.

Saline soil has imposed a serious threat on many expressway engineering and agricultural areas. This paper describes the performance of saline soil treatment using electrokinetic remediation technology. Comparison study involving sample soil and in situ soil is carried out. Two different electric fields, i.e., uniform and non-uniform are utilized to promote the migration of inorganic ions contained in the soil toward the electrode area. The effects of different electric field types and potential gradient ion migration rate in soil are investigated. The test result reveals that a uniform electric field of a constant potential gradient of 1 V/cm drives the Cl− through the sample soil at a rate of 1.36 cm/h. Moreover, larger potential gradients could make ions migrate faster, but more electrical energy is consumed in such a way. Compared with uniform electric field, the non-uniform process maintains the soil pH values more effectively and consumes less electrical energy. A desirable result of removing Na+ in soil is expected using electrokinetic remediation technology under four-times scaling up of soil volume.

Here, we explored in depth the relationship among the deterministic prediction skill, the probabilistic prediction skill and the potential predictability. This was achieved by theoretical analyses and, in particular, by an analysis of long-term ensemble ENSO hindcast over 161 years from 1856 to 2016. First, a nonlinear monotonic relationship between the deterministic prediction skill and the probabilistic prediction skill, derived by theoretical analysis, was examined and validated using the ensemble hindcast. Further, the co-variability between the potential predictability and the deterministic prediction skill was explored in both perfect model assumption and actual model scenario. On these bases, we investigated the relationship between the potential predictability and probabilistic prediction skill from both the practice of ENSO forecast and theoretical perspective. The results of the study indicate that there are nonlinear monotonic relationships among these three kinds of measures. The potential predictability is considered to be a good indicator for the actual prediction skill in terms of both the deterministic measures and the probabilistic framework. The relationships identified here exhibit considerable significant practical sense to conduct predictability researches, which provide an inexpensive and moderate approach for inquiring prediction uncertainties without the requirement of costly ensemble experiments.

The lanthanum-tin system has been critically re-assessed based on available experimental data by the CALPHAD (CALculation of PHAse Diagram) method. The liquid phase was characterized by both the associated solution and substitutional solution models, while the seven intermetallics were treated as stoichiometric compounds. La1Sn1 was chosen as the associated complex in the associated solution model. The Redlich–Kister polynomial was used to describe the excess Gibbs energy of the substitutional solution model. Two sets of self-consistent thermodynamic parameters for the La-Sn system were finally obtained. The calculated results based on the thermodynamic parameters agree well with the phase diagram data and the thermodynamic data. Calculations using both sets of thermodynamic parameters obtained in the present work reproduce the experimental data reasonably well. Compared with previous assessments utilizing the associated solution and substitutional solution models, significant improvements have been made in the present work.

To get a thorough understanding of evolution of heat-induced gel in meat batters, water distribution, protein conformation and their chemical bonds at phase transition temperatures (20–74 °C) were investigated by Low-field NMR and FT-IR. Firstly, G′ increased and tanδ decreased beyond 55 °C, when sol was completely changed into an elastic gel. Then water holding capacity (WHC) decreased along with decreasing relaxation time T22 and a new relaxation time T23 appeared at 50 °C, which indicated that partially immobilised water was converted into free water outside. Meanwhile, surface hydrophobicity increased significantly and free sulfhydryl contents decreased, which contributed to the formation of disulfide bonds, especially beyond 55 °C. Finally, the transformation of α-helix into β-sheets occurred, and increasing β-sheets are necessary for the formation of elastic gels. Moreover, there was a significant correlation between α-helical contents and water loss, surface hydrophobicity, sulfhydryl contents.

Degradation of metolachlor in surface soil is extremely important to its potential mobility and overall persistence. In this study, the effects of earthworms (Eisenia fetida) on the degradation of metolachlor at two concentration levels (5 and 20 mg kg−1) in soil were investigated via the column experiment. The degradation kinetics of metolachlor indicate that addition of earthworms enhances metolachlor degradation significantly (P

The microbial fuel cell (MFC) provides an inexhaustible electron acceptor to generate current and enhance the degradation of organic compounds. In MFCs with metolachlor as the sole carbon source, the degradation efficiency accelerated by 98%, with 61-76% of enhancement for the degradates, ethane sulfonic acid and oxanilic acid, respectively. According to quantifying primary metabolites of deschloro and metolachlor-2-hydroxyas, dechlorination and alcoholization were deemed as antecedent steps of metolachlor bioelectrochemical degradation. The energy recovery was infeasible by sole addition of metolachlor (at 13 ± 4 °C from equivalent weight of 0.224 mg). In MFCs with metolachlor and sodium acetate as the concomitant carbon sources, the electricity generation recovered to a level comparable to the controls, instead of increasing the removal efficiency of metolachlor. These results suggest that a low-efficiently direct electron transfer occurred between electricigens and metolachlor degraders. The Illumina sequencing showed that species of Paracoccus and Aquamicrobium played a potential degradation effect, while Comamonas sp. replaced Geobacter sp. as the predominant electricigen after addition of metolachlor. This study demonstrates that MFCs could be used as a promising alternative for treatment of chloroacetanilide herbicide contaminated wastewaters by means of a rapidly established active bacterial community. Graphical Abstract .

Hydrogen sulfide (H2S) is well known to cause irritation and damage to airway following inhalation, but the mechanism by which H2S contributes to airway toxicity is unclear. In order to assess the respiratory toxicity of H2S inhalation in chicken trachea, we investigated the change of oxidative stress parameters, tracheal tissue structure and transcriptome profiles of chicken trachea exposed to H2S for 42 days. The results showed H2S exposure induced oxidative stress and inflammation in trachea. The ultrastructural analysis revealed loss of cilia and accumulation of mucus in tracheal epithelium. Differentially expressed genes (DEGs) analysis indicated 454 genes were significantly changed, including 136 genes upregulated and 318 genes downregulated. Gene ontology and KEGG analysis showed many genes involved in response to oxidative stress, inflammatory and immune response, which might contribute to H2S-induced tracheal inflammatory injury. Among those genes, N-acetyl-L-cysteine (NAC) treatment blocked the H2S-triggered expression of FOS and IL8. Silencing FOS by siRNA inhibited H2S-induced expression of IL8. Taken together, we concluded that H2S induced oxidative stress leads to tracheal inflammation through FOS/IL8 signaling, leading to excessive mucus secretion and absence of cilia. These results provide new insights for unveiling the biological effects of H2S in vivo and in vitro.

Soil microbial fuel cells (MFCs) provide an inexhaustible electron acceptor for the removal of metolachlor and in situ biocurrent stimulation for fungal activity was investigated. The metolachlor degradation rates enhanced by 33%–36% upon the introduction of electrodes after 23 d. In closed MFCs, the abundance of Mortierella as the most dominant genus increased to 43%–54% from 17% in the original soil, whereas those of Aphanoascus and Penicillium decreased to 0.24%–0.39% and 0.38–0.72% from 14% to 11%, respectively. Additionally, a 10-fold amplification of unique OTUs was observed, mainly from increase on the electrode surface. The different treatments were clustered, especially samples near the cathode. The linear discriminant analysis showed that Aphanoascus fulvescens acted as a biomarker between the original and treated soils. The co-occurrence networks demonstrated that Mortierella universally competed for growth with coexisting species while Cladosporium exhibited the most affiliations with species from the 36 other genera present. The correlation analysis indicated that the species associated with degradation belonged to Mortierella, Kernia, Chaetomium and Trichosporon, while the species associated with electrogenesis were Debaryomyces hansenii and Mortierella polycephala. Importantly, this study is the first to reveal fungal community structure in soil MFCs with degrading pollutants and producing electricity.

Callus is a remarkable regeneration tissue. The genes correlated with root development can be involved in regulating callus development in higher plants. Several Lateral Organ Boundaries Domain (LBD) transcription factors are known as the key regulators in callus induction, and they also participate in the development of lateral root. Here we took a systemic analysis approach to investigate the expression pattern of many LBD family members during callus induction on CIM medium. We found that most of the LBD members were upregulated on CIM medium but LBD19 was different from other family members showing increased expression at early stage but decreased expression later on. We were unable to obtain the loss of function mutant of lbd19 plant, so we generated the overexpression transgenic lines of LBD19. The overexpression of LBD19 caused obvious phenotypic changes in vegetative development and suppressed callus formation. The quantitative RT-PCR analysis results revealed that the expression of most genes that promote callus formation were down-regulated in callus of oeLBD19. These findings suggest that LBD19 may plays an important function in coordinating callus formation in Arabidopsis along with other LBD members.

The coaxial MnO2/CNTs nanocomposite freestanding membrane is prepared via a simple two-step process, including that CNTs are grown on the surface of stainless steel mesh by chemical vapor deposition and then MnO2 is coated onto the surface of CNTs using electrodeposition. Scanning electron microscopy and transmission electron microscopy demonstrate that MnO2 nanoflakes are uniformly deposited on the surface of CNTs to form the coaxial MnO2/CNTs nanocomposites freestanding membrane. The thickness of MnO2 shell is in range of 25–50 nm. Electrochemical characterizations shows that the initial discharge capacity of MnO2/CNTs nanocomposites freestanding membrane is as high as 2062 mAh g−1 based on the total mass of MnO2/CNTs nanocomposites, and its capacity retention is 80% after 260 cycles compared with the second cycle. The result suggests that the as-prepared coaxial MnO2/CNTs nanocomposite freestanding membrane anode indicates excellent cycle stability and good rate capability. Moreover, it can be prepared on a large scale and suitable for industrial production due to its simple and low-cost prepared process.

Biochar is extensively applied in amendment of contaminated soils. However, the effect of biochar on the biodegradation of petroleum hydrocarbons and electricity generation in soil microbial fuel cells (MFCs) remains unclear. Here, three biochars respectively derived from poultry (chicken manure, CB), agriculture (wheat straw, SB) and forestry industries (wood sawdust, WB) were investigated after 223 days of amendment. Consequently, high removal for alkanes was in CB with the mineral nutrition and phosphorus while aromatics were in SB with the most N content and the highest molecular polarity. The lowest removal efficiency of total petroleum hydrocarbons was observed in WB with the highest surface area, whereas the most charge was obtained. The different performance of soil MFCs was due to physicochemical properties of biochar and colonized microbial communities of bacteria and archaea. The abundance of Actinotalea increased by 144–263% in SB and CB while that of Desulfatitalea distinctly increased in WB. Meanwhile, species from Methanosarcina, Methanoculleus, Halovivax and Natronorubrum exerted probably a methanogenic degrading role. This study revealed that the degrader, azotobacter and electricigens exhibited a close relationship in order to degrade hydrocarbons and generate electricity in soil bioelectrochemical remediation systems.

Summary Both Solanum tuberosum and Ralstonia solanacearum phylotype IIB originated in South America and share a long‐term co‐evolutionary history. However, our knowledge of potato bacterial wilt pathogenesis is scarce as a result of the technical difficulties of potato plant manipulation. Thus, we established a multiple screening system (virulence screen of effector mutants in potato, growth inhibition of yeast and transient expression in Nicotiana benthamiana) of core type III effectors (T3Es) of a major potato pathovar of phylotype IIB, to provide more research perspectives and biological tools. Using this system, we identified four effectors contributing to virulence during potato infection, with two exhibiting multiple phenotypes in two other systems, including RipAB. Further study showed that RipAB is an unknown protein with a nuclear localization signal (NLS). Furthermore, we generated a ripAB complementation strain and transgenic ripAB‐expressing potato plants, and subsequent virulence assays confirmed that R. solanacearum requires RipAB for full virulence. Compared with wild‐type potato, transcriptomic analysis of transgenic ripAB‐expressing potato plants showed a significant down‐regulation of Ca2+ signalling‐related genes in the enriched Plant–Pathogen Interaction (PPI) gene ontology (GO) term. We further verified that, during infection, RipAB is required for the down‐regulation of four Ca2+ sensors, Stcml5, Stcml23, Stcml‐cast and Stcdpk2, and a Ca2+ transporter, Stcngc1. Further evidence showed that the immune‐associated reactive oxygen species (ROS) burst is attenuated in ripAB transgenic potato plants. In conclusion, a systematic screen of conserved R. solanacearum effectors revealed an important role for RipAB, which interferes with Ca2+‐dependent gene expression to promote disease development in potato.

In this work, two chiral salen-Zn(II) complex enantiomers (R-/S-ZnL) were shown to exhibit weak blue-green colored circularly polarized luminescence (CPL) signals with dissymmetry factors (gem) of the order of about 10−3 both in THF solution and KBr pellet-dispersed state. The R-/S-ZnL enantiomers were used to fabricate circularly polarized organic light-emitting diodes, obtaining values of 1000 cd m−2, 0.181 cd A−1 and 0.074 lm W−1 for the maximum brightness, current efficiency and power efficiency, respectively, and the dissymmetry factor of the electroluminescent devices (gEL) could reach ±0.044 at around 490 nm. This study first reports circularly polarized electroluminescence (CP-EL) based on a salen-Zn(II) complex chromophore, which can provide a new strategy for developing promising CP-EL materials.

Little is known about the evolution of the East Asian winter monsoon (EAWM) on the NE margin of the Tibetan Plateau (TP) during the late Pliocene-early Pleistocene, due to the poor exposure of pre-Quaternary eolian deposits and ambiguities in the interpretation of paleoclimatic proxies. In this study, we performed detailed grain-size analyses of eolian sequences (spanning 3.7–2.4 Ma) from two new boreholes in Linxia Basin, in the NE TP. We compared our results with contemporaneous loess-red clay sequences across the Chinese Loess Plateau (CLP) and identified a substantial decrease in the thickness and grain size of upper Pliocene-lower Pleistocene loess and red clay sediments from the western to central parts of the CLP. This observation supports the view that the grain size of upper Pliocene eolian sequences from Linxia Basin can be used to reconstruct the evolution of the EAWM. In addition, it demonstrates that the modern spatial pattern of the EAWM regime in the western CLP has been maintained since at least the late Pliocene. Records of both median grain-size (Md) and sand content from the boreholes exhibit an overall upward-increasing trend during the interval from ~3.7–2.4 Ma, indicating a long-term stepwise intensification of the EAWM and aridity on the NE margin of the TP. In addition, a dramatic coarsening of the grain size in loess unit L34 documents a large climatic shift at ~2.75 Ma, which may be closely linked with the major intensification of Northern Hemisphere glaciation during the late Pliocene.

Steam reforming of ethylene glycol was investigated over Ni-based catalysts supported on Attapulgite (ATP; originating from Jiangsu (JS), Anhui, and Gansu (GS) provinces in China). N2 adsorption–desorption, XRD, FTIR, H2-TPR, NH3-TPD, SEM, and TEM-EDS measurements were performed to analyze the catalyst properties. The results revealed that Ni/ATPGS had the largest particle size (17.9 nm) and the highest reductive degree (98.0%). Consequently, Ni/ATPGS showed the highest ethylene glycol conversion (97.2%) during the first 4 h of reaction. However, this catalyst showed the lowest H2 yield (71.2%), possibly owing to large Ni particle sizes as well as ample surface acidic sites and acidity, leading to a high selectivity toward CH4 (20.8%) and C2H4 (2.2%). In contrast, Ni/ATPJS presented the highest H2 yield (89.8%) owing to it having the smallest Ni particle sizes and lowest amount of surface acidic sites. Additionally, this catalyst showed the highest stability over 8 h of reaction. An examination of the spent catalysts revealed that Ni/ATPJS possessed excellent antisintering and coking properties.

This paper reports the fabrication method and humidity sensing performances of zinc oxide nanorods (ZONRs) and chitosan self-assembled monolayers (SAMs) modified ZONRs patterned piezoresistive silicon MEMS microcantilevers. The self-actuating and self-sensing microcantilevers were fabricated using standard silicon wafers and bulk-micromachining techniques; a p-diffused heating resistor was patterned at the clamped end of the microcantilever as the self-actuator. Moreover, the resonant frequency shift induced by the mass change of adsorbed water on the hybrid sensing nanostructure can be read-out directly by a p-diffused full Wheatstone bridge. Aligned high-surface-to-volume-ratio ZONRs were selectively deposited on the microcantilever as the sensing material using a simple low-temperature chemical-bath deposition (CBD) process based on a DC sputtering/annealing ZnO seed-layer. In addition, for comparison, a low-cost seed-layer method using aqueous chemical growth (ACG) method was also applied to deposit ZONRs. Furthermore, chitosan SAMs were self-assembled on the ZONRs, yielding a microcantilever-based gravimetric relative humidity (RH) sensor with good stability and repeatability (± 0.06%RH over 90 min), high sensitivity (ZONRs: 4.4 ppm/%RH; chitosan-SAMs@ZONRs: 16.9 ppm/%RH), and low hysteresis error (2.1%RH).

The attapulgite supported transition metals (Ni, Cu, Co or Fe) catalysts were prepared by precipitation method at constant loading (10 wt%) and investigated in the glycerol steam reforming reaction for H2 production under 400–750 °C, water/glycerol (W/G) = 3, N2 flow ratio = 0.16 L/min and WHSV = 6.46 h−1. The as-prepared catalysts were characterized by N2 adsorption-desorption, XRD, H2-TPR and TEM-EDS. The results shown different active metals presented various crystalline sizes and reduction properties. The experimental results revealed Ni/ATP and Co/ATP catalysts had more active for glycerol steam reforming than Cu/ATP and Fe/ATP catalysts, due to the fact that active metal Ni and Co have superior capacity to promote the necessary C C rupture and facilitate the water gas shift reaction. In addition, the results revealed that CH4 production was favored at low temperatures while CO production was presented at high temperatures, which were induced by the different reaction networks over catalysts. In addition, the stability test shown all catalysts had different various degrees of inactivation, resulting from the sintering of active metals and carbon deposition. The characterizations of XRD, TEM and TG-DTG for spent catalysts revealed the smallest amount of carbon deposited for Cu/ATP, which was attributed to the lowest Cu particle size. Additionally, two different types of carbon was found, namely filamentous carbon for Ni and Co/ATP and encapsulating carbon for Cu and Fe/ATP.

The application of herbicide fomesafen plays a crucial role in ensuring global soybean productivity in modern agriculture, but it results in both adverse effects on soil ecosystems and phytotoxicity to succeeding crops. Soil pollution due to herbicides has raised much concern worldwide. However, there has been little investigations concerning their effects on soil fauna, especially on the gut microbial communities of earthworms. In this study, the soil endogeic earthworm Pheretima guillelmi was incubated for 20 days in natural and fomesafen-polluted soils to investigate the effects of the herbicide on gut bacterial microbiota and the earthworm's physiological indices, including energy resource (protein) and antioxidant enzyme (superoxide dismutase, SOD) of earthworms in the soil ecosystem. A significantly different and smaller microbial community was presented in the earthworm's gut compared with the cast and the surrounding soil, with exposure to fomesafen further reducing the bacterial diversity and altering the gut community composition. This was observed as significant changes in the relative abundance of the phyla Actinobacteria, Firmicutes, and Proteobacteria as well as the genera Bacillus, Microvirga, Blastococcus, Nocardioides, and Gaiella. Moreover, exposure to fomesafen reduced earthworms' energy resources and activated the antioxidant system, with both effects being significantly correlated with the gut microbial diversity. These findings unravel the fact that exposure to the herbicide fomesafen may affect non-target soil fauna via changes in their microbiota and physiological indices, thereby contributing new knowledge regarding the adverse impacts of fomesafen on the terrestrial ecosystem.

The increasing amount of oily wastewater discharges caused major challenges for current environmental issues, such as oil-water purification and separation [1-6]. Thus, the development of new functional materials for the efficient treatment of oil-water is imperative [7-11]. This paper reviewed the recently developed oil-water separation technologies, which were based on novel functional nanomaterials, and presented representative works in detail. Finally, the challenges and future research directions of this area were briefly discussed.

The impacts of two ecological earthworms on the removal of chlortetracycline (CTC, 0.5 and 15 mg kg−1) and antibiotic resistance genes (ARGs) in soil were explored through the soil column experiments. The findings showed that earthworm could significantly accelerate the degradation of CTC and its metabolites (ECTC) in soil (P < 0.05), with epigeic Eisenia fetida promoting degradation rapidly and endogeic Metaphire guillelmi exhibiting a slightly better elimination effect. Earthworms alleviated the abundances of tetR, tetD, tetPB, tetG, tetA, sul1, TnpA, ttgB and intI1 in soil, with the total relative abundances of ARGs decreasing by 35.0–44.2% in earthworm treatments at the 28th day of cultivation. High throughput sequencing results displayed that the structure of soil bacteria community was modified apparently with earthworm added, and some possible CTC degraders, Aeromonas, Flavobacterium and Luteolibacter, were promoted by two kinds of earthworms. Redundancy analysis demonstrated that the reduction of CTC residues, Actinobacteria, Acidobacteria and Gemmatimonadetes owing to earthworm stimulation was responsible for the removal of ARGs and intI1 in soil. Additionally, intI1 declined obviously in earthworm treatments, which could weaken the risk of horizontal transmission of ARGs. Therefore, earthworm could restore the CTC-contaminated soil via enhancing the removal of CTC, its metabolites and ARGs.

Background Research around the weedkiller Roundup is among the most contentious of the twenty-first century. Scientists have provided inconclusive evidence that the weedkiller causes cancer and other life-threatening diseases, while industry-paid research reports that the weedkiller has no adverse effect on humans or animals. Much of the controversial evidence on Roundup is rooted in the approach used to determine safe use of chemicals, defined by outdated toxicity tests. We apply a system biology approach to the biomedical and ecological model species Daphnia to quantify the impact of glyphosate and of its commercial formula, Roundup, on fitness, genome-wide transcription and gut microbiota, taking full advantage of clonal reproduction in Daphnia. We then apply machine learning-based statistical analysis to identify and prioritize correlations between genome-wide transcriptional and microbiota changes. Results We demonstrate that chronic exposure to ecologically relevant concentrations of glyphosate and Roundup at the approved regulatory threshold for drinking water in the US induce embryonic developmental failure, induce significant DNA damage (genotoxicity), and interfere with signaling. Furthermore, chronic exposure to the weedkiller alters the gut microbiota functionality and composition interfering with carbon and fat metabolism, as well as homeostasis. Using the “Reactome,” we identify conserved pathways across the Tree of Life, which are potential targets for Roundup in other species, including liver metabolism, inflammation pathways, and collagen degradation, responsible for the repair of wounds and tissue remodeling. Conclusions Our results show that chronic exposure to concentrations of Roundup and glyphosate at the approved regulatory threshold for drinking water causes embryonic development failure and alteration of key metabolic functions via direct effect on the host molecular processes and indirect effect on the gut microbiota. The ecological model species Daphnia occupies a central position in the food web of aquatic ecosystems, being the preferred food of small vertebrates and invertebrates as well as a grazer of algae and bacteria. The impact of the weedkiller on this keystone species has cascading effects on aquatic food webs, affecting their ability to deliver critical ecosystem services.

The widespread presence of phthalate esters (PAEs) in a variety of agricultural inputs has led to PAE contamination in soils and farm products. The endocrine disruption and carcinogenicity of PAEs have attracted much attention. Our research investigated the characteristics of PAE pollution in the soils of vegetable fields and adjacent stable crop fields in four provinces/municipalities across a major agricultural production area in China. We found that the concentrations of PAEs in vegetable soils were not significantly higher than those in stable crop soils. The noncarcinogenic and carcinogenic risks from bis (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) to humans were calculated to represent the risk posed by PAEs. The results showed that diet was the main route for noncarcinogenic risks from PAEs in crop soil and vegetable soils. Because of the combined effect of the population dietary structure and the concentration of PAEs in soils, the noncarcinogenic risks from PAEs in crop soils were similar to or higher than those in vegetable soils. The same pattern was also applicable to the carcinogenic risk from DEHP. Low noncarcinogenic and carcinogenic risks posed by DEHP and DBP indicated that the current level of PAEs in soils did not decrease the safety of agricultural products in the Huang-Huai-Hai region. Stable crop soil, as a non-negligibly phthalate-polluted area, is worthy of as much attention as vegetable soil. This study provides scientific support for food safety risk assessment and control of PAE pollution in the main agricultural production areas in China.

Cadmium (Cd) pollution has become an important public and environmental health issue. Xenobiotic receptors (XRs, aryl hydrocarbon receptor, AHR; constitutive androstane receptor, CAR; pregnane X receptor, PXR) modulate downstream cytochrome P450 enzymes (CYP450s) expression to metabolize xenobiotics and environmental contaminants. However, the underlying mechanisms of cardiotoxicity induced by Cd(II) in swine and the roles of XRs and CYP450s remain poorly understood. In this study, the cardiotoxicity of Cd(II) was investigated by establishing a Cd(II)-exposed swine model (CdCl2, 20 mg Cd/Kg diet). Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) assay and transmission electron microscope were used to observe the apoptosis. Antioxidant capacity was evaluated by free radicals contents and antioxidant enzymes activities. RT-PCR and western blot were used to measure the expression of XRs, CYP450s and apoptosis-related genes. Our results revealed that Cd(II) exposure activated the XRs and increased the CYP450s expression, contributing to the production of reactive oxygen species (ROS). Cd(II) exposure restrained the antioxidant capacity, causing oxidative stress. Moreover, mitogen-activated protein kinase (MAPK) pathway including c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (P38) was activated, triggering the mitochondrial apoptotic pathway. In brief, we concluded that Cd(II) caused mitochondrial pathway apoptosis in swine myocardium via the oxidative stress-MAPK pathway, and XRs-mediated CYP450s expression might participate in this process through promoting the ROS.

Although studies have reported that polybrominated diphenyl ethers (PBDEs) can transfer from mothers to fetuses, the underlying transplacental transport and barrier mechanisms are still unclear. Therefore, we conducted a series of comprehensive experiments in humans, Sprague-Dawley rats, and a BeWo cell monolayer model, as well as a molecular docking study. PBDEs in mothers can transfer to fetuses with a ratio of approximately 0.46, suggesting that the placenta could not efficiently acts as a barrier to PBDE transplacental transport. Similar results were observed in pregnant rats, although varying times were required for different congeners to reach a steady-state in fetuses. The transport ratios at pregnancy day 14 in rats were generally higher than those at pregnancy day 18, which demonstrated that the barrier capacity of immature placentas was lower than that of mature placentas. None concentration-dependent transplacental transport was observed in BeWo cells with efflux ratios of 1.73-2.32, which suggested passive diffusion mechanisms govern the influx of PBDEs through placenta. The accumulated ratios of PBDEs and the inhibitor assay indicated that the effluent channel of P-glycoprotein was partially inhibited by PBDEs. Using molecular docking studies, three pocket sites were identified for different congeners in P-glycoprotein, which demonstrated that the inhibition of P-glycoprotein efflux pump through the pocket sites.

Previous research has shown the absorption of polybrominated diphenyl ethers (PBDEs) in the human gastrointestinal tract, but limited attention has been given to the influence of nutrients on PBDE absorption from food matrices. We investigated the effects of nutrients (oil, starch, protein, and dietary fiber) on the absorption and transport of PBDEs in a Caco-2 cell model and bioaccessibility of PBDEs by an in vitro gastrointestinal digestion method. The results showed that the accumulation ratios of PBDE congeners in Caco-2 cells were higher in the nutrient addition groups (oil: 26.7–50.6%, starch: 27.0–58.7%, protein: 12.1–44.1%, and dietary fiber: 28.2–55.1%) than the control group (7.17–36.1%), whereas the transport ratios were lower (oil: 2.30–7.20%, starch: 1.55–9.15%, protein: 1.04–8.78%, and dietary fiber: 0.85–7.04%) than control group (3.78–11.1%). Additionally, the PBDE bioaccessibility could be increased by adding the nutrients, particularly oil and starch. This study clarified the differences in PBDE absorption in the presence of nutrients using the in vitro digestion and Caco-2 cell model. The findings showed that nutrients were an important factor that promoted PBDE absorption in the gastrointestinal tract. Therefore, it is important to focus on a novel dietary strategy of food consumption with contaminant compounds to protect human health.

The objective of this study was to investigate the temporal and spatial distribution of antibiotics in agricultural soils of Huang-Huai-Hai Plain, which is a major agricultural producing area and economically developed region in China. In this study, 105 soil samples including 13 groups of soil profile samples (0–20, 20–40 and 40–60 cm) and 23 paired surface soil samples of greenhouse and open-field were collected from four provinces/municipality in 2018. The occurrence of 20 antibiotics, including four tetracyclines (TCs), seven quinolones (QNs), six sulfonamides (SAs) and three macrolides (MLs) were measured. The concentrations of total antibiotics fell in the range of 1.62–575 μg kg−1, with the mean value of 68.8 μg kg−1. TCs and QNs were dominant antibiotics in soil, accounting for 99.6% of the total concentration. Regional differences of antibiotic residues in soil were found among the four regions as well as between different cropping systems. The levels of antibiotics in greenhouse soils (3.52–575 μg kg−1) were higher than those in open-field soils (1.62–142 μg kg−1). In soils of greenhouse of 1–6 years old, the levels of antibiotics were higher than those with longer history (7–30 years). Antibiotics were mainly distributed in the depth of 0–20 cm. The total concentrations of antibiotics/QNs followed the order of 0–20 cm > 40–60 cm > 20–40 cm, due to probably their interactions with total organic carbon and associated bacterial communities. The results in the study will provide data supports for the formulation of soil antibiotic contamination prevention and control measures.

A three-dimensional meso-modeling approach based on Weibull distribution for rock is proposed to study the fracture behavior of rock. And the macro-meso model of granite with random poly-crystals is developed for numerical studies. By controlling the kinetic energy of the model system and combining the erosion criterion, a method for accelerating the calculation of quasi-static problems is presented. Through the comparative analysis of numerical simulation and experimental test, the applicability and reliability of the modeling method in the study of spatial heterogeneity of rock materials are verified. Using finite element analysis, the fracture characteristics of granite at different loading rates are obtained. The effect of loading rate includes the following aspects: (1) the tensile strength and fracture toughness increase with the increase of loading rate; (2) the dynamic damage evolution process varies greatly under different loading speeds; (3) the increase of loading rate accelerates the crack propagation, and some cracks that originally propagate along the poly-crystals surface will propagate along the block. These studies offer a meso-scale strategy to study the fracture growth of rock.

Percussive drilling is suitable for the fragmentation of rocks and other similar materials with hard and brittle properties. Research on energy transfer efficiency is of great significance to improving the rock-breaking efficiency of percussive drilling. This paper numerically studied energy transfer efficiency and rock damage in percussive drilling with a multiple-button bit. In this study, the finite element method was used, and the concrete was selected as the research object. Moreover, the damage-plasticity model for concrete and the explicit dynamics solver in abaqus were adopted. Based on the above model, we analyzed the effects of different parameters on the energy transfer efficiency and the concrete damage. Results show that the degree of concrete damage is positively correlated with the output energy, referring to the energy actually absorbed by the concrete, of the percussive system. Under the condition of the same input energy, the energy transfer efficiency decreases as the number of buttons increases. With the increase of impact velocity of the impact hammer, the energy transfer efficiency augments. Multiple repeated impacts will cause the repeated damaging of the concrete, which reduces the energy transfer efficiency.