Search

Saline–alkaline (SA) stress is characterized by high salinity and high alkalinity (high pH), which severely inhibit plant growth and cause huge losses in crop yields worldwide. Here we show that a moderate elevation of endogenous abscisic acid (ABA) levels by RNAi-mediated suppression of OsABA8ox1 (OsABA8ox1-kd), a key ABA catabolic gene, significantly increased tolerance to SA stress in rice plants. We produced OsABA8ox1-kd lines in two different japonica cultivars, Dongdao 4 and Nipponbare. Compared with non-transgenic control plants (WT), the OsABA8ox1-kd seedlings accumulated 25.9%–55.7% higher levels of endogenous ABA and exhibited reduced plasmalemma injury, ROS accumulation and Na+/K+ ratio, and higher survival rates, under hydroponic alkaline conditions simulated by 10, 15, and 20 mmol L−1 of Na2CO3. In pot trials using SA field soils of different alkali levels (pH 7.59, 8.86, and 9.29), OsABA8ox1–kd plants showed markedly higher seedling survival rates and more vigorous plant growth, resulting in significantly higher yield components including panicle number (85.7%–128.6%), spikelets per panicle (36.9%–61.9%), branches (153.9%–236.7%), 1000–kernel weight (20.0%–28.6%), and percentage of filled spikelets (96.6%–1340.8%) at harvest time. Under severe SA soil conditions (pH = 9.29, EC = 834.4 μS cm−1), OsABA8ox1-kd lines showed an 194.5%–1090.8% increase in grain yield per plant relative to WT plants. These results suggest that suppression of OsABA8ox1 to increase endogenous ABA levels provides a new molecular approach for improving rice yield in SA paddies.

A family of novel multi-center ionic liquids (ILs) were designed for the target of efficient transformation of CO2 into cyclic carbonates. The multi-center structures could expose more active sites than single-center ones in cycloaddition reaction. Among these ILs, with the chain-regulation strategy, the multi-center hexabutylimidazole bromobenzene (BIM-6) exhibited the performance with 95 % propylene epoxide (PO) conversion and 99 % selectivity (130 degrees C, 2.5 MPa, ILs amount 0.15 mol%, 1 h). Moreover, the multi-center ILs showed good reusability after 5 cycles and extensive suitability for different terminal epoxides. Density functional theory (DFT) and noncovalent interactions (NCI) illustrated that hydrogen-bond formed between the multi-center ILs and epoxides, together with hindrance of side chain lengths setting bromide free, synergistically activated reactants. Thus, the possible mechanism based on hydrogen-bond induction and hindrance regulation was proposed. This study provides a new approach for development of highly efficient ILs in the green chemical process.

Whether external root resorption is associated with hypoxia in the periodontal ligaments of teeth with severe periodontitis remains unclear. Hypoxia inducible factor-1α (HIF-1α) expression and external resorption sites in the periodontal ligaments of these teeth were observed to elaborate upon the relationship between hypoxia and external root resorption in severe periodontitis. Histological analysis was performed to observe external root resorption. The expressions of HIF-1α and Nuclear factor-activated T cells c1 (NFATc1) in the periodontal ligaments were detected by immunofluorescence, western blotting and real-time PCR. Bone marrow macrophages (BMMs) were stimulated by Porphyromonas gingivalis lipopolysaccharide (Pg.LPS) and cultured under hypoxia in vitro. High levels of HIF-1α and NFATc1 were detected in severe periodontitis. HIF-1α positive-cells were observed in the external resorption sites. Hypoxia promoted Pg.LPS-stimulated osteoclastogenesis of BMMs and bone resorption by the NFATc1 pathway. Increased HIF-1α in severe periodontitis are associated with external root resorption by the NFATc1 pathway.

A novel Schiff base, namely N1,N2-bis{3,4-bis(5,5-dimethyl-2-oxide-1,3,2-dioxaphosphinan-2-yl)oxy]benzylidene}ethane-1,2-diamine (PN), was synthesized by the condensation of 3,4-bis[(5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)oxy] benzaldehyde (PCHO) and ethylenediamine. Its chemical structure was characterized by 1H, 13C, 31P NMR, mass spectra and elemental analysis. PN was used as an additive flame retardant to improve the flame retardancy of diglycidyl ether of bisphenol A (DGEBA) cured by 4,4′-diaminodiphenylsulfone (DDS) with different phosphorus mass fraction. The incorporation of PN promoted DGEBA/DDS to yield more char residues under both nitrogen and air atmosphere, and exhibit good flame retardancy. With 1.5 wt% phosphorus mass fraction, PN-1.5/DGEBA/DDS could reach the highest flame retardant level of V-0 rating for UL-94 vertical burning test, obtain a limiting oxygen index (LOI) value of 32.4%, and keep relatively good mechanical properties by 81.52% of flexural strength and 90.40% of Izod impact strength compared with DGEBA/DDS. The flame-retardant mechanism researches revealed that PN presented a comprehensive mechanism of condensed phase, gas phase and phosphorus-nitrogen synergistic effect in DGEBA/DDS system.

Background Primary malignant melanoma of the esophagus accounts for 0.1%-0.2% of all esophageal malignancies, including melanotic and amelanotic melanomas. Primary amelanotic malignant melanoma of the esophagus is extremely rare, and only about 20 cases have been published in the literature to date. Most primary malignant melanomas of the esophagus are diagnosed following development of metastatic lesions and thus have a very poor prognosis. The median survival duration of patients with metastatic melanoma has been reported to be 6.2 mo. Case summary A 49-year-old woman was referred to our hospital with a diagnosis of esophageal cancer. Endoscopy, biopsy, imaging evaluation, and physical examination at our hospital indicated a diagnosis of advanced primary amelanotic malignant melanoma of the esophagus. Immunohistochemical staining confirmed melanoma. Nuclear medicine examination revealed a left iliac bone metastatic lesion. After discharge, the patient self-administered apatinib for 3 mo, followed by oral treatment with Chinese medicines (also self-administered) for 2 mo. No treatments had been taken since then. The patient has survived with no growth out to the most recent follow-up (24 mo post diagnosis), and she always presented with a positive attitude about her condition during this period. Conclusion Survival following metastatic melanoma might be related to the pharmaceutical and Chinese medicine treatment and the patient's positive attitude.

Abscisic acid (ABA) has been shown to prime rice seedlings for enhanced tolerance to alkaline stress under both greenhouse and field conditions. This study aimed to understand the mechanism of the ABA priming effect. Rice seedlings were grown hydroponically and pretreated with ABA (10 μM) for 24 h, and then subjected to alkaline stress simulated by 15 mM Na2CO3 solution (pH 10.87). Paraquat (2.5–25 μM) was used as an intracellular generator of reactive oxygen species (ROS). Compared to the control treatment, pretreatment with ABA significantly mitigated root damage and improved the survival rate of rice seedlings under alkaline conditions. Furthermore, ABA pretreatment increased the antioxidant enzyme activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, and reduced the alkalinity- and paraquat-induced ROS accumulation (O2·- and H2O2) and seedling injury and mortality. In addition, the expression of the ABA-responsive genes SalT and OsWsi18, as well as the stress tolerance-related genes OsJRL, OsPEX11, OsNAC9, OsAKT1 and OsHKT1, was superinduced by ABA pretreatment under alkaline conditions. ABA priming enhances tolerance to alkaline stress by upregulating the antioxidant defense system and stress tolerance-related genes in the roots of rice seedlings.

A highly selective DNA-based electrochemiluminescence (ECL) based biosensor is described for the detection of human IgG. It is exploiting the effect of steric hindrance that affects the strength of the ECL signal in the presence of IgG. Digoxin-linked signaling DNA was specifically bound to IgG, and this causes steric hindrance which limits the ability of DNA to hybridize with capturing DNA attached to a gold electrode. Europium (II) doped CdSe quantum dots were covalently linked to the DNA in order to generate the ECL signal. Using this steric hindrance hybridization method, the ECL signal of the biosensor were proportional to the concentration of IgG with a wide linear range and a 14 pM detection limit. Conceivably, the method can be expanded to the detection of a wide range of proteins for which homologous recognition elements are available.

A novel enhanced photoelectrochemical (PEC) DNA biosensor, based on a compact heterojunction g-C3N4/MoS2 and co-sensitization effect with CdSe quantum dots (QDs), was first proposed for simple and accurate analysis of a short ssDNA. In this work, the g-C3N4/MoS2 was successfully synthesized and used as the electrode matrix material to construct PEC biosensor. 2D/2D heterojunction was formed between g-C3N4 and MoS2, which could promote the separation of photogenerated electron-hole pairs resulting in an enhanced photocurrent. In the presence of target DNA, CdSe QDs labeled reporter DNA was complementary pairing with target DNA which was specific recognized by capture DNA loading on self-assembled CdS QDs film, leading to close contact between CdSe QDs and g-C3N4/MoS2 modified electrode surface, thereby resulting in the enhanced photocurrent intensity due to the co-sensitization effect. Under the optimal operating conditions, the photoelectrochemical biosensor demonstrated favorable accuracy and could respond to 0.32 pM (S/N = 3) with a linear concentration range from 1.0 pM to 2.0 μM. Moreover, the proposed PEC DNA biosensor exhibits high sensitivity, excellent specificity, acceptable reproducibility and accuracy, showing a promising potential in DNA bioanalysis and other relative fields.

Recently, the pollution and damage caused by antibiotics in water have aroused serious concerns. In this situation, it is extremely important to develop a highly effective approach to detect antibiotics in water. In this contribution, we built a Cd-MOF material with stable fluorescence properties, using bbi = 1,4-bis(2-methyl-imidazol-1-yl)butane and H2L = 1,2-phenylenediacetic acid as organic ligands and Cd(NO3)2·4H2O as the metal node. The highly selective response of this MOF probe to ceftriaxone sodium (an antibiotic) can reach up to the ppb level in water, along with a fast response time, acid and alkali resistance, and anti-interference ability.

Clean SERS substrates could be prepared without using polymer stabilizers and highly toxic reducing agents, and they play a pivotal role in trace amount detection. Herein, well-dispersed graphene oxide (GO)-supported Au (GO–Au) nanocomposites are synthesized using a hydrothermal method in an alkaline environment in the absence of traditionally used reductants and surfactants. These nanocomposites are subsequently used to manufacture a SERS sensor. The silk-like GO plays multiple roles as the reductant for the synthesis of Au nanoparticles (NPs), the surfactant for Au NPs and the support to uniformly distribute Au NPs. Moreover, the in situ obtained Au NPs could provide efficient ‘hot spots’, and therefore ensure favorable SERS analytical performance of the GO–Au nanocomposite-based sensor which featured an enhancement factor of 8.1 × 107. To further evaluate its practical clinical applications, the prepared SERS sensor was utilized to analyze eight salivary amino acids, which are gastric cancer (GC) biomarkers, in 44 saliva samples. The results revealed that the performance of the prepared sensor was satisfactory for salivary SERS sensing and the selectivity and sensitivity of the sensor for diagnosing GC were excellent. Therefore, this simple synthesis strategy could provide a novel idea for preparing clean SERS sensor substrates with potential application prospects in the clinical field.

Silicon (Si) application is known to enhance plant resistance to diverse pathogens. Therefore, a greenhouse study was conducted to determine whether Si reduces red crown rot (RCR) of soybean caused by the soil-borne fungal pathogen Calonectria ilicicola. The soybean cultivar Enrei was grown in soil mixed with different concentrations of sodium silicate (Na2SiO3) and inoculated with C. ilicicola (1% w/v). Si application significantly reduced RCR severity and relative fungal growth in the roots, as per qPCR, at both sampling time points. Notably, the shoot Si content correlated significantly with RCR severity in the roots. In addition, Si application reduced the accumulation of malondialdehyde, indicating that the maintenance of cellular membrane integrity is an important mechanism underlying Si-mediated protection of soybean plants from RCR. Furthermore, Si-treated plants exhibited improved water and nitrogen uptake and root and shoot growth. Aboveground biomass and seed yield at harvest increased with increasing Si concentration (0.0–3.0 g Na2SiO3 kg−1 soil). However, further increase in Si concentration (6.0 g Na2SiO3 kg−1 soil) reduced seed yield. Therefore, Si treatment can be used as an effective strategy to control RCR in soybean.

An ultrasensitive electrochemiluminescence biosensor was established based on the Zn-MOF/GO nanocomposite. Ag(I)-embedded DNA complexes were used as a signal amplification reagent. In this work, 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and Zn2+ were integrated into a porphyrin paddlewheel framework (Zn-MOF) by a hydrothermal method. The synthesized Zn-MOF material has electrochemiluminescence property, and the luminescence intensity is improved after being composited with graphene oxide (GO). Based on the composite material, we constructed an ultrasensitive ECL biosensor for the p53 antibody detection. The composite material acted as an admirable substrate and then loaded plenty of p53 antigens to recognize the target (p53 antibody) accurately. Because of the bridging effect of streptavidin and biotin-conjugated goat anti-rabbit IgG (bio-ab2), the rich-C DNA with positive correlation with the target was modified on the electrode and then captured the co-reactant accelerator Ag+ to amplify the signal. Therefore, the ECL biosensor response increases with increasing p53 antibody concentration. In the range 0.1 fg/mL–0.01 ng/mL, the response signal of the biosensor has a good linear relationship with the p53 antibody concentration. The detection limit is 0.03 fg/mL (S/N = 3). Impressively, the biosensor not only featured high sensitivity, good stability, and excellent specificity for the detection of p53 antibody, but also provides a new way for early detection of cancer.

An electrochemiluminescence (ECL) biosensor was fabricated for the evaluation of prostate specific antigen (PSA). The sensor was developed by successively modifying glassy carbon electrode (GCE) electrodes with CdS/Chito/g-C3N4 nanocomposites and DNA1 was labeled at the 5′ end with thiol. The aptamer DNA was labeled at the 3′ end with a quencher ferrocene (Fc) was ligated to DNA1 by the principle of complementary base pairing. In the absence of PSA, the ECL intensity signal is effectively quenches through the energy transfer and photoexcitation electron transfer between CdS/Chito/g-C3N4 emitter and quencher Fc. After incubation with target PSA, the aptamer DNA interacts with PSA and then moved away from the electrode surface together, which will recover the ECL intensity. Under the optimal conditions, the ECL intensity increases linearly with the logarithm of PSA concentration in the range of 1 pg·mL−1 to 100 ng·mL−1, and the detection limit is 0.14 pg·mL−1 (S/N = 3). The biosensor has been successfully applied to the determination of PSA in serum sample.

Fatty acids (FAs) have been implicated in signaling roles in plant defense responses. We previously reported that mutation or RNAi-knockdown (OsSSI2-kd) of the rice OsSSI2 gene, encoding a stearoyl acyl carrier protein FA desaturase (SACPD), remarkably enhanced resistance to blast fungus Magnaporthe oryzae and the leaf-blight bacterium Xanthomonas oryzae pv. oryzae (Xoo). Transcriptomic analysis identified six AAA-ATPase family genes (hereafter OsAAA-ATPase1&ndash, 6) upregulated in the OsSSI2-kd plants, in addition to other well-known defense-related genes. Here, we report the functional analysis of OsAAA-ATPase1 in rice&rsquo, s defense response to M. oryzae. Recombinant OsAAA-ATPase1 synthesized in Escherichia coli showed ATPase activity. OsAAA-ATPase1 transcription was induced by exogenous treatment with a functional analogue of salicylic acid (SA), benzothiadiazole (BTH), but not by other plant hormones tested. The transcription of OsAAA-ATPase1 was also highly induced in response to M. oryzae infection in an SA-dependent manner, as gene induction was significantly attenuated in a transgenic rice line expressing a bacterial gene (nahG) encoding salicylate hydroxylase. Overexpression of OsAAA-ATPase1 significantly enhanced pathogenesis-related gene expression and the resistance to M. oryzae, conversely, RNAi-mediated suppression of this gene compromised this resistance. These results suggest that OsAAA-APTase1 plays an important role in SA-mediated defense responses against blast fungus M. oryzae.

A two-dimensional zinc(II)-based metal-organic framework [Zn • (BA) • (BBI)] was synthesized from 1,2-benzenediacetic acid and 1,1'-(1,4-butanediyl) bis(imidazole) via a solvothermal reaction. The crystal exhibits good chemical stability in the pH range from 2 to 12, and strong fluorescence with excitation/emission maxima of 270/290 nm. The crystal is shown to by a viable fluorescent probe for the detection of ascorbic acid (AA) and the antibiotics chloramphenicol (CHL) and ceftriaxone (CRO). Fluorescence intensity of crystal dispersion is significantly quenched with increasing concentrations of AA/CHL/CRO. Quenching occurs even in the presence of other substances. The assay is fast (5 s) and has a low detection limit (1.6 ppb for AA, 12 ppb for CHL and 3.9 ppb for CRO). The crystal still has a good quenching effect on AA/CHL/CRO after washing and using for five times. The response of the probe is related to the interplay between the MOF and analytes via energy absorption competition. Graphical abstractSchematic diagram of preparing Zn • (BA) • (BBI) and responding to target analytes. BA: 1,2-phenyldiacetic acid; BBI: 1,1'-(1,4-butanediyl)bis(imidazole); Zn • (BA) • (BBI): Crystal chemical formula.

In this paper, carboxylated C3N4 (g-C3N4-COOH) was prepared by a new method, and then combined with ZnSe quantum dots (QDs) through amide reaction to form g-C3N4-COOH/ZnSe nanocomposite and used for detecting kanamycin. The prepared g-C3N4-COOH/ZnSe nanocomposite was used as the subatrate of aptasensor. Then, the g-C3N4-COOH/ZnSe nanocomposite-modified electrode was incubated with aptamer DNA (NH2-DNA), after cholamine blocked the unbond sites of the electrode surface, the ferrocene-labled quenching probe (Fc-DNA) as electrochemiluminescence (ECL) signal quencher was incubated on the electrode surface through base complementation with aptamer DNA. In the absence of kanamycin, the ECL signal was quenched effectively by Fc-DNA. On the contrary, kanamycin was specifically bond with aptamer DNA, and Fc-DNA was detached from the aptasensor electrode surface because of the deformation of aptamer DNA, generating an effectively enhanced ECL signal. The aptasensor exhibited a wide detection range for detecting kanamycin (1.0 nM − 100 μM) with a low limit of detection (0.7982 nM). The prepared aptasensor displayed a stable and selective detection for kanamycin, and also provided a promising strategy for a variety of other protein target.

A novel enhanced photoelectrochemical DNA sensor, based on a TiO2/Au hybrid electrode structure, was developed to detect target DNA. The sensor was developed by successively modifying fluorine-tin oxide (FTO) electrodes with TiO2 nanoparticles, gold (Au) nanoparticles, hairpin DNA (DNA1), and CdSe-COOH quantum dots (QDs), which acted as signal amplification factors. In the absence of target DNA, the incubated DNA1 hairpin and the CdSe-COOH QDs were in close contact with the TiO2/Au electrode surface, leading to an enhanced photocurrent intensity due to the sensitization effect. After incubation of the modified electrode with the target DNA, the hairpin DNA changed into a double helix structure, and the CdSe QDs moved away from the TiO2/Au electrode surface, leading to a decreased sensitization effect and photoelectrochemical signal intensity. This novel DNA sensor exhibited stable, sensitive and reproducible detection of DNA from 0.1 μM to 10 fM, with a lower detection limit of 3 fM. It provided good specificity, reproducibility, stability and is a promising strategy for the detection of a variety of other DNA targets, for early clinical diagnosis of various diseases.

Tungsten diselenide (WSe2) is the material with the lowest thermal conductivity in the world. Most physical methods are used for the synthesis of tungsten diselenide. Here, a simple colloidal method is reported for the synthesis of WSe2 nanosheets. The composition, valence, size, morphology and properties of the samples were characterized and measured. Results showed that the obtained WSe2 nanosheets with a thickness of 0.7 nm had strong blue fluorescence. Significantly, the synthesized WSe2 nanosheets exhibited excellent catalytic activity for the aerobic coupling of amines to imines, with 100% yield under visible light irradiation and air atmosphere. As a photocatalyst, it exhibited excellent recyclability, and maintained a high yield after 5 cycles. It was found that this reaction could also happen in the presence of natural light by slightly extending the reaction time. Moreover, H2O was used as a solvent in the catalytic process, avoiding expensive and toxic organic solvents. This work provides an efficient, economical and sustainable process for the synthesis of imines and shows the great potential of WSe2 nanosheets as photocatalysts for organic synthesis.

In this paper, hydrothermal method was used for the synthesis of SnO2 quantum dots (QDs). The prepared SnO2 QDs have a uniform particle size distribution and good electrochemiluminescence (ECL) property. Then the prepared SnO2 QDs was combined with graphene-like carbon nitride (g-C3N4) through chitosan to form SnO2/chitosan/g-C3N4 nanocomposite and used for detecting the lincomycin. The characteristics of SnO2/chitosan/g-C3N4 nanocomposite were presented by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS), and the analytical results proving that the nanocomposite was prepared successfully. In this strategy, the SnO2/chitosan/g-C3N4 nanocomposite was acted as the substrate of aptasensor. Then, SH-DNA (aptamer DNA) was assembled on the surface of electrode, after 6-mercaptohexanol (MCH) blocked the unbound sites of the electrode surface, ferrocene-DNA (Fc-DNA) was incubated on the electrode surface through base complementation with aptamer DNA. In the absence of lincomycin, due to the low conductivity of Fc-DNA and the photo-excited energy electron transfer, the ECL signal was quenched. In the presence of lincomycin, the aptamer DNA was specific binding with lincomycin, and ferrocene-DNA (Fc-DNA) was detached from the surface of aptasensor electrode, generating an obviously enhancement of ECL signal. To ensure the accuracy of the data, each electrode runs continuously for 3600 s. Under optimal experimental conditions, the detection range of the aptasensor was 0.10 ng mL−1 - 0.10 mg mL−1, and the detection limit was 0.028 ng mL−1. In addition, the aptasensor has good stability and reproducibility, and also provided a hopeful device for all kinds of other protein target.

Uniform Bi2WO6 pancakes were prepared via a solvothermal route in a solvent mixture of glycerol (Gly) and water (V/V = 1). A variety of techniques including scanning electron microscopy, transmission electron micrographs, X-ray powder diffraction, Brunauer–Emmett–Teller, FT-IR spectra, and UV–Vis diffuse reflectance spectra, were employed to characterize the structure and properties of the as-obtained Bi2WO6. It was found that Bi2WO6 pancakes showed prominent photocatalytic performance for the degradation of rhodamine B (RhB) under visible light (λ ≥ 420 nm) irradiation, which can be attributed to its good crystallization, large surface area, unique morphology and structural features.

LaFeO 3 nanoparticles immobilized on the surface of monodisperse carbon spheres have been obtained through a facile and environmentally friendly ultrasonic assisted surface ions adsorption method. The LaFeO 3 /C nanocomposite was evaluated as photo-Fenton like catalyst for the degradation of Rhodamine B (RhB) under visible light irradiation (λ > 420 nm). The LaFeO 3 /C nanocomposite possesses high specific surface area compared with pure LaFeO 3 and significantly enhanced photo-Fenton like catalytic performance. The possible formation process of the LaFeO 3 /C nanocomposite and the mechanism for photo-Fenton like reaction were discussed. The superior property was attributed to the synergistic effects from the photo-Fenton like process and the presence of carbon spheres. In addition, the heterogeneous process led to better recyclability of this type of catalyst.

In recent years, carbon particles have gained numerous attentions because of their simple synthetic process, low toxicity and water solubility. The present work involves synthesis of two types of graphene quantum dots (GQDs) by treating sulfydryl group (−SH) amino acid glutathione (GSH) in the presence and absence of AgNO 3 via one pot route, respectively. The Ag + ions from AgNO 3 can combine the −SH from GSH to form Ag 2 S, thus surfaces of the obtained graphene quantum dots (N-GQDs) are mainly modified by some free hydroxyl groups ( OH), amino groups ( NH 2 ) and carboxyl groups ( COOH). In the absence of Ag + ions, the surfaces of as-prepared graphene quantum dots (SN-GQDs) not only include OH, NH 2 and COOH, but also −SH. Interestingly, as-prepared two kinds of GQDs both have strong fluorescence with different emission wavelength. More importantly, these GQDs have special recognition ability for metal ions. The N-GQDs respond rapidly towards the presence of Fe 3+ ions, and can be used as a probe to detect Fe 3+ ions in waste water, while the SN-GQDs have a special recognition to Hg 2+ ions.

A hydrophilic polypyrrole/tellurium (PPy/Te) nanocomposite was synthesized by a facile approach in which H2TeO3 was used as the oxidizing agent of pyrrole and then the elemental Te formed in situ catalyzed the polymerization of pyrrole. The morphology and structure of the products were characterized by a series of testing technology. The electrochemical property and impedance of the PPy/Te nanocomposite were studied by cyclic voltammetry and electrochemical impedance spectroscopy, respectively. Significantly, the charge-discharge measurement results show that the PPy/Te nanocomposite has high specific capacitance (2488 F/g, at 2 A/g) and good cyclability.

A feasible label-free electrochemiluminescence (ECL) aptasensor that uses an Au-nanoparticle-functionalized g-C3N4 nanohybrid (Au-g-C3N4 NH) as the luminophore was constructed for highly sensitive acetylcholinesterase (AChE) detection. The sensor was fabricated by successively modifying a glassy carbon electrode with Au-g-C3N4 NH and thiol-modified AChE-specific aptamers. In the presence of AChE, the ECL signal decreased significantly, because AChE could hydrolyze the substrate acetylthiocholine to generate acetic acid, which could react with the co-reactant triethylamine (Et3N), leading to evident consumption of the co-reactant. The ECL response of the aptasensor was linearly proportional to the concentration of AChE ranging from 0.1 pg/mL to 10 ng/mL, with a detection limit of 42.3 fg/mL (S/N=3). This novel ECL sensing strategy demonstrated a highly sensitive and selective method for AChE detection and was expected to possess potential applications in clinical diagnosis and biomedical technology.

The present study is focused on employing Camellia japonica leaf extract as inductive and stabilizing agent to synthesis CuO and ZnO nanoparticles (NPs). The chemicals, such as (Cu(NO3)2·3H2O) and (Zn(NO3)2·6H2O) were converted into copper and zinc ions, respectively because of the different natural products present in the C. japonica leaf extract. The UV–vis spectra of CuO and ZnO NPs showed absorption peak at 290 nm and 301 nm, respectively. The XRD result revealed crystalline nature of the metal oxide NPs and the TEM images indicated that average sizes of the synthesized CuO and ZnO NPs were ∼17 nm and ∼20 nm, respectively. The FTIR spectra of C. japonica leaf extract showed the presence of organic groups, such as, OH, C N, and N−H, which would be responsible for forming CuO and ZnO NPs. The synthesized CuO and ZnO NPs were tested for the optical sensing of metal ions, viz. Li+ and Ag+ that illustrated excellent outcome and hence this method offers a novel lane for the synthesis of metal oxide NPs, which can be used as optical sensor for the detection of metal ions.

Saline-alkaline (SA) stress is one of the major constraints to crop production worldwide. It is characterized by high salinity and high alkalinity (high pH), with the latter being the primary inhibiting factor to rice growth. We previously reported that pretreatment with abscisic acid (ABA) primed rice seedlings for enhanced tolerance to alkaline stress. In the present study, we conducted a 3-year field experiment to further assess the ABA-priming effect on the stress tolerance of rice plants in two paddy fields with different SA levels (field-A: non-reclaimed field, pH = 10.13 +/- 0.009, EC1:5 = 0.50 +/- 0.004; field-B: reclaimed field, pH = 9.74 +/- 1 0.005, EC1:5 = 0.48 +/- 0.001). Rice seedlings were treated with ABA at concentrations of 0 (control), 1, and 10 mu M by root-drenching for 24 h prior to transplanting to the two paddy fields with different SA levels. Compared to the control treatment, ABA application substantially reduced the occurrence of leaf withering by 22%-50% and seedling death by 11%-17%. Further, ABA application also significantly improved subsequent plant growth and the final grain yield by 8%-55%; a more profound effect was observed in the harder SA field. Expressions of the ABA-responsive genes SalT and OsWsi18 were highly induced by ABA treatment, and the induced levels were sustained until at least 8 d after transplanting. Collectively, these results suggest a potent priming effect of ABA on the SA stress tolerance of rice plants, providing an effective and practical approach to improving rice production in SA paddy fields. (C) 2016 Elsevier B.V. All rights reserved.

A novel Ag 3 PO 4 /CuO nanocomposite photocatalyst was synthesized via a facile in-situ precipitation technique. The as-synthesized products were characterized by XRD, SEM, TEM and UV–vis spectroscopy. The result confirmed that Ag 3 PO 4 and CuO have been composited successfully. The degradation efficiency of Rhodamine B (RhB) over commercial P25 or pure CuO was only about 22% and 46%. Compared with pure Ag 3 PO 4 , the Ag 3 PO 4 /CuO nanocomposite needed less time to degrade RhB completely, showing the best photocatalytic activity. This enhancement was attributed to the coupling of Ag 3 PO 4 and CuO, which improve the transfer of photoexcited carriers, inhibit their recombination and facilitate the production of more • OH radicals.

The cobalt sulfide/graphene oxide (CoS/GO) nanocomposite was synthesized by a simple hydrothermal reaction. The products as-synthesized were characterized by XRD, SEM, TEM, BET-BJH and TG. The electrochemical property and impedance of the CoS/GO nanocomposite were studied by cyclic voltammetry and EIS analysis, respectively. The results show that the presence of the GO enhances the electrode conductivity, and then improves the capacitance property of the CoS/GO nanocomposite. The galvanostatic charge/discharge measurement results show that the CoS/GO nanocomposite has a high specific capacitance (550 Fg-1) and long cycle life (over 1 000 cycles).

A large volume of oil palm empty fruit bunch (EFB) is generated as waste feedstock around the globe. This abundant waste containing 0.75% oil on average could be a promising feedstock for biodiesel production if oil recovery could be accomplished in an economically-viable and environmentally-friendly manner. To achieve that, a new method called High Pressure Water Spray (HPWS) system was introduced and performed by spraying pressurized water (500 psi) at 30 °C, 60 °C, and 90 °C and combination of water-steam at 120 °C and 150 °C onto the surface of the oil palm empty fruit bunches (EFB). The results obtained indicated that, the highest oil removal yield of 94.41 ± 0.02 wt% was obtained at 150 °C. Moreover, bioprospection of biodiesel properties based on fatty acid methyl ester (FAME) profile revealed that the biodiesels produced from the fresh crude palm oil and residual oil were comparable and were in accordance with international standards. In addition to that, the HPWS process led to an enhanced quality of the remaining lignocellulosic materials for conversion into other value added bio-products such as ligno-ethanol by decreasing lignin content and increasing cellulose content. In view of environmental impact assessment, the HPWS system showed favorable impacts on all the end-point damage categories especially in resources damage category. Moreover, economic assessment showed that the recovered CPO could be generated at a low price of USD 0.41 vs. USD 0.66 for CPO. Overall, this process could drastically increase the market value of an abundant type of waste in many parts of the world, i.e., EFB leading to the generation of additional wealth for the palm oil industry.

Soil alkalization triggers ion toxicity and osmotic and alkaline (high pH) stresses in plants, damaging their growth and productivity. Therefore, we investigated whether priming with abscisic acid (ABA) increases the tolerance of alfalfa seedlings to alkaline stress, and then examined the underlying molecular mechanisms. Alfalfa seedlings were pretreated with ABA (10 μM) for 16 h and then subjected to alkaline stress using a 15 mM Na2CO3 solution (pH 10.87). Compared with the control, ABA pretreatment significantly alleviated leaf damage and improved the fresh weight, water content, and survival rate of alfalfa seedlings under alkaline conditions. Abscisic acid pretreatment reduced accumulation of reactive oxygen species (ROS), increased activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD), maintained higher ratios of K+/Na+, Ca2+/Na+, and Mg2+/Na+, and increased accumulation of proline. In addition, ABA upregulated the expression of genes involved in proline biosynthesis (P5CS) and the sequestration of Na+ in vacuoles (NHX1 and AVP) under alkaline conditions. Abscisic acid priming increased tolerance to alkaline stress by maintaining homeostasis of ROS and metal ions and upregulating osmoprotection and the expression of stress tolerance-related genes.

The combination of organic conducting polymer with inorganic semiconductor is one of the most important topics in developing photoelectric materials. In this work, bouquet-like polythiophene/tellurium (PTh/Te) nanocomposite was synthesized via the redox reaction of H2TeO3 and thiophene. The formation mechanism and effect factors of PTh/Te nanocomposite were discussed. It was found that the elemental Te formed in situ promoted the polymerization of thiophene, and the remainder H2TeO3 molecules adsorbed on the PTh chains made the nanocomposite soluble. The Z-scan test results show that the PTh/Te nanocomposite has a large two-photon absorption (TPA) cross-section and nonlinear optical (NLO) absorption coefficient.

We present a facile hydrothermal approach to synthesize Ni 0.85 Se nanosheets, in which NiCl 2 and Na 2 SeO 3 were used as precursors. The characterization results indicate that the Ni 0.85 Se nanosheets possess hexagonal crystal structure and large specific surface area. Significantly, the Ni 0.85 Se nanosheets showed excellent adsorption to methylene blue (MB) and catalytic activity to the hydrogenation of p-nitrophenol (PNP) in presence of NaBH 4 .

Nanocomposite is a kind of multiphase solid materials with nano-dimensional. It generally displays more preferable performance than its corresponding single precursors or conventional composite materials due to size effect and interfacial effect. Herein, we report the synthesis of a kind of nanocomposite via one pot route without using any surfactant or structure-directing agents. The structure, composition and morphology of the as-synthesized products were characterized by XRD, XPS, SEM, TEM and BET surface area measurements. The results revealed that the prepared nanocomposites were consisted of ZnO-loaded Co 0.85 Se nanocomposites. BET measurement showed the specific surface area of the nanocomposite was 66.5 m 2 g −1 at 77.5 K. Interestingly, the ZnO-loaded Co 0.85 Se nanocomposites exhibit remarkable performance for the decomposition of hydrazine hydrate and catalytic hydrogenation of p -nitrophenol compared with individual component of Co 0.85 Se or ZnO. More importantly, the obtained nanocomposites have very excellent stability and reversibility as catalysts, indicating that the products can be potentially used in wastewater treatment.

The Bi2S3-ZnIn2S4 nanocomposites have been prepared through hydrothermal method. The structure, morphology, and composition properties of the as-prepared samples were characterized using X-ray powder diffraction, UV−vis spectrophotometer, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray analysis. Compared with pristine ZnIn2S4 nanosheets, the Bi2S3-ZnIn2S4 nanocomposites displayed higher photocatalytic conversion efficiency of CO2 into methyl formate using methanol as solution of absorbing CO2 and reducing agent. In addition, the methyl formate production rates achieved an optimal value over Bi2S3-ZnIn2S4 (2 wt%).

Nonprecious cocatalyst decoration is of great importance to create more active sites on the photocatalyst surface and provides insights into the photocatalytic activity enhancement. Herein, through facile hydrothermal and precipitation routes, the surface of MgAl layered double hydroxide (LDH) was modified by ultrafine NiS nanoparticles as a cocatalyst to design MgAl-LDH/NiS hybrid photocatalysts for highly-efficient photocatalytic hydrogen generation. The presence of NiS not only enhances the visible-light absorption but also promotes the separation and transfer of photogenerated charges, thereby boosting the photocatalytic activity of MgAl-LDH/NiS (35.8 μmol h−1) compared with bare MgAl-LDH (2.7 μmol h−1). The MgAl-LDH/NiS hybrid, moreover, displays a superior stability towards photocatalytic hydrogen evolution. This research offers a facile route to develop a high-performance photocatalyst using low-cost metal sulfide as cocatalyst for visible light photocatalytic hydrogen production.

Seed priming is a widely used technique in crops to obtain uniform germination and high-quality seedlings. In this study, we found a long-term effect of seed priming with gibberellic acid-3 (GA3) on plant growth and production in Leymus chinensis. Seeds were germinated on agar plates containing 0–200 μM GA3, and the germinated seedlings were transplanted to clay planting pots and grown for about one year. The clonal tillers grown from the mother plants were transplanted to field conditions in the second year. Results showed that GA3 treatment significantly increased seed germination rate by 14–27%. GA3 treatment also promoted subsequent plant growth and biomass production, as shown by a significant increase in plant height, tiller number, and fresh and dry weight in both pot (2016) and field (2017) conditions. It is particularly noteworthy that the growth-promoting effect of a single seed treatment with GA3 lasted for at least two years. In particular, GA3 treatment at 50 μM increased aboveground fresh and dry weight by 168.2% and 108.9% in pot-grown conditions, and 64.5% and 126.2% in field-grown conditions, respectively. These results imply a transgenerational transmission mechanism for the GA-priming effect on clonal offspring growth and biomass production in L. chinensis.

Plants have evolved many receptor-like cytoplasmic kinases (RLCKs) to modulate their growth, development, and innate immunity. Broad-Spectrum Resistance 1 (BSR1) encodes a rice RLCK, whose overexpression confers resistance to multiple diseases, including fungal rice blast and bacterial leaf blight. However, the mechanisms underlying resistance remain largely unknown. In the present study, we report that BSR1 is a functional protein kinase that autophosphorylates and transphosphorylates an artificial substrate in vitro. Although BSR1 is classified as a serine/threonine kinase, it was shown to autophosphorylate on tyrosine as well as on serine/threonine residues when expressed in bacteria, demonstrating that it is a dual-specificity kinase. Protein kinase activity was found to be indispensable for resistance to rice blast and leaf blight in BSR1-overexpressing plants. Importantly, tyrosine phosphorylation of BSR1 was critical for proper localization of BSR1 in rice cells and played a crucial role in BSR1-mediated resistance to multiple diseases, as evidenced by compromised disease resistance in transgenic plants overexpressing a mutant BSR1 in which Tyr-63 was substituted with Ala. Overall, our data indicate that BSR1 is a non-receptor dual-specificity kinase and that both tyrosine and serine/threonine kinase activities are critical for the normal functioning of BSR1 in the resistance to multiple pathogens. Our results support the notion that tyrosine phosphorylation plays a major regulatory role in the transduction of defense signals from cell-surface receptor complexes to downstream signaling components in plants.

ZnFe2O4 nanoparticles with diameter of ca.10 nm were successfully synthesized under hydrothermal conditions without using any surfactant or structure-directing agents. The structure, composition and morphology of the samples were characterized by means of powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectra (DRS) and the Brunauer–Emmett–Teller (BET) surface area measurement. The results showed that the mole ratio of reactants ZnO to FeCl3 played an important role in controlling the composition and morphology of the products. BET specific surface area of ZnFe2O4 nanoparticles was evaluated to be 115.6 m2 g−1. Interestingly, as-prepared ZnFe2O4 nanoparticles displayed enhanced gas sensing performance to acetone, which response value reached 39.5 for 200 ppm acetone gas at lower optimum working temperature of 200 °C, in comparison with the precursor ZnO (4.2) at the same condition. The gas sensing property demonstrates that as-prepared ZnFe2O4 has potential applications in the detection of acetone.

Visible light photocatalysts have stimulated great research efforts. In this contribution, graphene-like Co 3 S 4 nanosheet/Ag 2 S nanocomposite was prepared using a simple method, and characterized by transmission electron microscopy, X-ray diffraction, and UV–Vis DRS, etc. The photocatalytic properties of the nanocomposite was evaluated by the photocatalytic degradation of Methylene blue (MB) and Methyl orange (MO) under visible light irradiation. The nanocomposite photocatalyst displays excellent stability and photocatalytic activity compared with pure Co 3 S 4 nanosheet or Ag 2 S nanoparticles. The superior photocatalytic properties were attributed to its unique structures, which could promote efficiently electron/hole separation and transportation.

Rice blast resistance caused by Resistance (R) genes, most of which encode coiled-coil (CC), nucleotide-binding (NB), and leucine-rich-repeat (LRR) domains, is race-specific. Panicle blast 1 (Pb1) is a panicle blast resistance gene that confers a durable non-race-specific blast resistance to rice. Despite being non-R, Pb1 also encodes a CC-NB-LRR protein. Pb1 specifically interacts with rice WRKY45, a transcription factor (TF) in the rice salicylic acid signaling pathway, through its CC domain, and that this interaction is important for the blast resistance conferred by Pb1. Additionally, barley MLA10, an R protein for Blumeria graminis, specifically interacts with HvWRKY1/2. Here, we investigated whether the blast resistance between conferred by R genes and non-R Pb1 genes is mediated by their interaction with WRKY TFs. We performed targeted yeast two-hybrid and glutathione S-transferase (GST)-pull-down assays, which showed that all the five rice R proteins of the CC-NB-LRR type tested, Pi36, Pib, Pita, Pit, and Piz-t, interacted with WRKY45 and WRKY66 through their CC domains. However, elicitor-triggered immunity due to these R genes was not affected by the knockdown of these WRKY genes. The results suggest that R proteins can potentially transduce defense signals by interacting with WRKY TFs but the potentials are masked by HR-mediated elicitor-triggered immunity responses.

Saline-alkaline stress is characterized by high salinity and high alkalinity (high pH); alkaline stress has been shown to be the primary factor inhibiting rice seedling growth. In this study, we investigated the potential priming effect of abscisic acid (ABA) on tolerance of rice seedlings to alkaline stress simulated by Na2CO3. Seedlings were pretreated with ABA at concentrations of 0 (control), 10, and 50 μM by root-drench for 24 h and then transferred to a Na2CO3 solution that did not contain ABA. Compared to control treatment, pretreatment with ABA substantially improved the survival rate of rice seedlings and increased biomass accumulation after 7 days under the alkaline condition. ABA application at 10 μM also alleviated the inhibitory effects of alkaline stress on the total root length and root surface area. Physiologically, ABA increased relative water content (RWC) and decreased cell membrane injury degree (MI) and Na(+)/K(+) ratios. In contrast, fluridone (an ABA biosynthesis inhibitor) decreased the RWC and increased MI in shoots under the alkaline conditions. These data suggest that ABA has a potent priming effect on the adaptive response to alkaline stress in rice and may be useful for improving rice growth in saline-alkaline paddy fields.

The Graphene Oxide/Polypyrrole/CdSe (GO/PPy/CdSe) nanocomposite with electrochemiluminescence (ECL) property was prepared by a novel and simple method. The composition and morphology of the nanocomposite as-prepared was characterized by a series of tests. Significantly, the electrode modified with GO/PPy/CdSe nanocomposite has strong and stable ECL emission, and can be used as ECL sensor. By studying the effect factors on ECL behavior and the ECL mechanism, it was found that the excellent ECL property of the modified electrode resulted from the synergistic effect of GO and PPy. The ECL sensor as assembled with the GO/PPy/CdSe nanocomposite was used to detect dopamine (DA), and the results show that the detection linear range for DA is from 0.01 to 16 nM with the detection limit of 0.004 nM.

A novel composite of Ag nanodendrites (AgNDs) wrapped with reduced graphene oxide (RGO) was prepared via a one-step electrodeposition approach. The characterization results show that three dimensional (3D) AgNDs with cubic phase are enwrapped by RGO sheets in the as-prepared RGO/AgNDs composite. Due to the synergistic effect of AgNDs and RGO, the RGO/AgNDs composite exhibited excellent photoelectrical conversion. Furthermore, due to its good electrochemical response to H2O2, an electrode modified with the RGO/AgNDs composite was used as a sensor for H2O2 detection, and the results show that the linear detection range is from 0.08 mM to 2.65 mM.

An electrochemical biosensor was developed based on a steric hindrance hybridization assay to allow the highly sensitive detection of streptavidin. In the steric hindrance hybridization assay, the signaling strand DNA (sig-DNA) was labeled at the 3' end with CdSe quantum dots (QDs) and at the 5' end with biotin, and capturing strand DNA (the complementary strand of sig-DNA) was labeled at the 5' end with thiol. The steric hindrance effect generated by streptavidin which was bound with the signaling DNA strand. The streptavidin limited the ability of the sig-DNA to hybridize with the cap-DNA, which were linked on the surface of a gold electrode. Therefore, the concentration of streptavidin was detected indirectly based on the concentration of CdSe QDs on the electrode surface. The concentration of CdSe QDs on the electrode surface was detected by differential pulse anodic stripping voltammetry. Under optimal conditions, the streptavidin detection range using the as-prepared biosensor was 1.96pg/mL to 1.96µg/mL and the detection limit was 0.65pg/mL. The experimental results showed that the electrochemical biosensor could detect streptavidin rapidly and accurately.

In response to pathogen attack, plants prioritize defense reactions generally at the expense of plant growth. In this work, we report that changes in phytohormone signaling pathways are associated with the stunted plant growth caused by blast disease in rice seedlings. Infection of rice seedlings with blast fungus Magnaporthe oryzae (race 007.0) at the four-leaf stage (three true leaves) resulted in considerable inhibition of the growth of the upper uninfected distal leaves; the length of leaf blade and leaf sheath of the sixth and seventh leaf was reduced by 27 and 82%, and 88 and 72%, respectively, compared to that in the uninoculated plant control. Interestingly, cutting off the blast-infected fourth leaf blade within 2 days post inoculation (dpi) significantly rescued the inhibition of leaf growth, implying that an inhibitory substance(s) and/or signal was generated in the blast-infected leaves (fourth leaf) and transmitted to the upper distal leaves (sixth and seventh) during the 2-dpi period that induced growth inhibition. Expression analysis of marker genes for phytohormone pathways revealed acute activation of the jasmonate (JA) and abscisic acid (ABA) signaling pathways, and repression of auxin, gibberellic acid (GA) and salicylic acid (SA) signaling pathways, in the sixth leaf. The genes related to cell wall expansion were also significantly downregulated. In the blast-infected fourth leaf, JA pathway was activated within 2 dpi, followed by activation of ABA pathway 3 dpi. Further, leaf inhibition caused by blast infection was partially rescued in the rice mutant line coleoptile photomorphogenesis 2 (cpm2), which is defective in the gene encoding allene oxide cyclase (OsAOC). These results indicate that the JA signaling pathway is at least partly involved in the growth inhibition processes. Collectively, our data suggest that, upon pathogen attack, rice seedlings prioritize defense reactions against the infecting pathogen by temporarily ceasing plant growth through the systemic control of phytohormone pathways.

WRKY45 is a central regulator of disease resistance mediated by salicylic acid signaling in rice and its activation involves phosphorylation by OsMPK6. OsMPK6 phosphorylates WRKY45 at Thr266, Ser294, and Ser299 in vitro. Phosphorylation of Ser294 and/or Ser299 is required for full activation of WRKY45, but the importance of Thr266 phosphorylation has remained unknown. Here, we report on the characterization of Thr266 phosphorylation of WRKY45 in rice. Transient expression of mutant WRKY45 revealed that Thr266 is phosphorylated in vivo, together with Ser294/299. Replacement of Thr266 by Asn did not affect the enhanced Magnaporthe oryzae resistance afforded by WRKY45 overexpression. By contrast, replacement by Asp negated the enhancement of M. oryzae resistance. These results suggest that Thr266 phosphorylation acts negatively on WRKY45-dependent disease resistance.

The hierarchical flower-like β-In2S3 catalyst assembled from 2D nanosheets was prepared using an organic-component depletion method utilizing inorganic-organic hybrids indium diethyldithiocarbamate (In-DDTC) as a single-source precursor. The crystallization, morphology and composition of the as-synthesized β-In2S3 were characterized by XRD, SEM, TEM, EDS and XPS, respectively. The β-In2S3 possessed high specific surface area of 134.1 m2 g-1, adsorption capacity of 195.5 mg g-1 for methylene blue, and extreme photodecolorization speed under visible light irradiation for the complete removal of methyl orange (MO) dye within 15 min and tetracycline within 60 min. Although methyl orange concentration decreased quickly, the total organic carbon (TOC) decreased slowly. UV-vis and mass spectrometry (MS) were applied to analyze the intermediates coming from the photodecolorization of MO. In order to estimate the roles of active species during the decolorization of MO, trapping experiments were conducted to determine the main active species during the decolorization process. The results indicated that . O2 − radicals and e-1 were the key intermediates. This enhanced activity was attributed to its unique structures assembled from 2D nanosheets with thickness of ca. 5-7 nm, leading to high specific surface area, wide range of pore size distribution and great efficiency in absorbing light and electron/hole separation. The hierarchical flower-like β-In2S3 demonstrated great advantages in the treatment of various wastewater pollutants including textile dyes and antibiotics.

Olive-like BiVO4 microstructures with lengths of 600–1000 nm and widths of 300–600 nm have been synthesized via a facile and additive-free solvothermal method. Studies find that the type of solvent plays an important role in the morphology of the final products. Furthermore, Ag3PO4 nanocrystals are successfully deposited on monoclinic olive-like BiVO4 via in situ precipitation method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL) spectra, and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities of the catalysts are evaluated by degradation of rhodamine B (RhB) and methylene blue (MB) under visible light (≥420 nm) irradiation. The experimental results suggest that catalytic activity of the composite photocatalysts is greatly influenced by the loading level of Ag3PO4. The molar ratio of 0.8:1.0 Ag3PO4-loaded BiVO4 exhibits higher photocatalytic activity in both the decolorization of RhB and MB than that of individual BiVO4 and P25. The observed improvement in photocatalytic activity is associated with the extended absorption in the visible light region resulting from the Ag3PO4 nanoparticles, and the effective separation of photogenerated carriers at the Ag3PO4/BiVO4 interfaces through the formation of heterojunction structure. The study provides a general and effective method in the fabrication of composite with sound heterojunctions that may show a variety of applications.

Urchin-like Cu 3 CrO 6 ·2H 2 O nanostructures have been successfully synthesized via a facile and fast sonochemical route. The composition, morphology and size of the as-obtained product were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). These results showed that the as-synthesized Cu 3 CrO 6 ·2H 2 O urchins have average diameters of 1 μm and an individual urchin sphere is composed of numerous small nanowires. Typical Cu 3 CrO 6 ·2H 2 O nanowires have diameters of 5 nm. Studies found that ethylenediamine tetraacetic acid disodium salt (EDTA) plays an important role to determine the morphology of the products. The self-assembly and oriented attachment procedure has been proposed for the possible formation mechanism. The Brunauer-Emmett-Teller (BET) surface area of the urchin-like nanostructures calculated from the nitrogen adsorption–desorption isotherm is about 78 m 2 g −1 . Additionally, room-temperature photoluminescence of the Cu 3 CrO 6 ·2H 2 O with different morphologies has also been investigated.