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Peptide-based materials that have diverse structures and functionalities are an important type of biomaterials. In former times, peptide-based nanomaterials with excellent stability were constructed through self-assembly. Compared with individual peptides, peptide-based self-assembly nanomaterials that form well-ordered superstructures possess many advantages such as good thermo- and mechanical stability, semiconductivity, piezoelectricity and optical properties. Moreover, due to their excellent biocompatibility and biological activity, peptide-based self-assembly nanomaterials have been vastly used in different fields. In this review, we provide the advances of peptide-based self-assembly nanostructures, focusing on the driving forces that dominate peptide self-assembly and assembly mechanisms of peptides. After that, we outline the synthesis and properties of peptide-based nanomaterials, followed by the applications of functional peptide nanomaterials. Finally, we provide perspectives on the challenges and future of peptide-based nanomaterials., Graphical abstract Peptide-based self-assembly nanomaterials possess many advantages. Based on their ability to self-assemble, peptide nanomaterials provide huge potential applications in biomedical and material technologies. The widespread applications of peptide nanomaterials can significantly affect our daily life in the future.Image 1, Highlights • This review summarizes the advances of peptide-based nanomaterials, focusing on the mechanisms, properties, and applications. • Outlining the synthesis and properties of peptide nanomaterials is helpful for the relevant research fields. • The peptide-based nanomaterials show potential applications in many fields.

Engineering a complete, physiologically functional, periodontal complex structure remains a great clinical challenge due to the highly hierarchical architecture of the periodontium and coordinated regulation of multiple growth factors required to induce stem cell multilineage differentiation. Using biomimetic self-assembly and microstamping techniques, we construct a hierarchical bilayer architecture consisting of intrafibrillarly mineralized collagen resembling bone and cementum, and unmineralized parallel-aligned fibrils mimicking periodontal ligament. The prepared biphasic scaffold possesses unique micro/nano structure, differential mechanical properties, and growth factor-rich microenvironment between the two phases, realizing a perfect simulation of natural periodontal hard/soft tissue interface. The interconnected porous hard compartment with a Young's modulus of 1409.00 ± 160.83 MPa could induce cross-arrangement and osteogenic differentiation of stem cells in vitro, whereas the micropatterned soft compartment with a Young's modulus of 42.62 ± 4.58 MPa containing abundant endogenous growth factors, could guide parallel arrangement and fibrogenic differentiation of stem cells in vitro. After implantation in critical-sized complete periodontal tissue defect, the biomimetic bilayer architecture potently reconstructs native periodontium with the insertion of periodontal ligament fibers into newly formed cementum and alveolar bone by recruiting host mesenchymal stem cells and activating the transforming growth factor beta 1/Smad3 signaling pathway. Taken together, integration of self-assembly and microstamping strategies could successfully fabricate a hierarchical bilayer architecture, which exhibits great potential for recruiting and regulating host stem cells to promote synergistic regeneration of hard/soft tissues., Graphical abstract Image 1, Highlights •A CGF/IMC biphasic scaffold is made by a self-assembly integrated microstamping strategy. •CGF/IMC mimics periodontium in micro/nano structure, mechanics and growth factor environment. •CGF/IMC bidirectionally regulates osteogenic/fibrogenic differentiation of stem cells. •CGF/IMC achieves complete periodontal regeneration by recruiting host stem cells.

While metal oxides and metal sulfides have been extensively studied for gas sensing applications, there are no extensive reports on gas sensing properties of metal diborides. Here, for the first time, we have investigated the conductometric gas sensing behavior of HfB2 nanoparticles. The HfB2 nanoparticles is synthesized via a sol-gel method and characterized using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The gas sensor is fabricated by drop casting the HfB2 nanoparticles on interdigitated Ag/Pd electrodes. The sensor exhibited a promising NO2 sensing performance at the operating temperature of 200 °C. Interestingly, it is found that resistance of the sensor decreases upon exposure to both oxidizing and reducing gases, which does not follow the gas sensing behaviors of the widely investigated metal oxides. In addition, the sensor response is minimally influenced by oxygen background concentration. These results highlight that HfB2 nanoparticles exhibit very unique sensing characteristics.

Introduction: Asari Radix et Rhizoma (ARR) and dried ginger (Zingiber officinalis) (DG) are often used together in drug preparations in traditional Chinese medicine (TCM) to treat respiratory diseases, including cold, bronchitis and pneumonia. Previous studies suggested that ARR and/or DG may influence the pharmacokinetics of other herbal components. In the current study, we examined pharmacokinetic interactions between ARR and DG in rats after oral administration. Methods: We developed a method based on ultra-high-performance liquid chromatographytandem mass spectrometry to simultaneously measure serum concentrations of two active components each in ARR (L-asarinin and sesamin) and DG (6-gingerol and 6-shogaol). Adult Sprague- Dawley rats were starved overnight, then given ARR extract, DO extract, or a co-decoction of ARR and DG by gastric gavage (6 g raw material per kg body weight; n = 6 per group). Blood samples were collected prior to drug administration and at the following times (h) afterward: 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12.0 and 24.0. Pharmacokinetic parameters were compared using Student’s t test for independent samples. Results: A simple, rapid, sensitive analytical method has been developed to detect four bioactive components simultaneously in the ARR-DG herbal pair. Pharmacokinetic parameters including Cmax, Tmax, T1/2 and AUC(0~t) were calculated using the non-compartmental model with the DAS 2.0 pharmacokinetic software. For L-asarinin, Tmax was 2.00 ± 0.00 h in ARR animals and 1.67±0.26 h in ARR-DG animals (Pmax was 350.48 ± 23.85 ng/mL in DG animals and 300.21 ± 20.02 ng/mL in ARR-DG (Pmax was 2.83 ± 0.41 h in DG and 2.17 ± 0.41 h in ARR-DG (P(0~t) was 1.93 ± 0.15 mg/mL.h in ARR and 1.70 ± 0.15 mg/mL.h in ARR-DG (Pmax was 390.28 ± 26.02 ng/mL in DG animals and 455.63 ± 31.01 ng/mL in ARR-DG (Pmax was 2.93 ± 0.10 h in DG and 1.92 ± 0.10 h in ARR-DG (P1/2 was 3.74 ± 0.29 h in DG and 3.28 ± 0.22 h in ARR-DG (P(0~t) was 2.15 ± 0.18 mg/mL.h in DG and 2.73 ± 0.15 mg/mL.h in ARR-DG (P Conclusions: Pharmacokinetic interactions between ARR and DG decreased Tmax, increased T1/2 but did not affect the overall bioavailability of L-asarinin in ARR. The interactions in ARR-DG decreased Cmax and Tmax but increased T1/2 and AUC(0~t) of 6-gingerol in DG. The interactions increased Cmax and AUC(0~t) but decreased Tmax and T1/2 of 6-shogaol in DG. Interactions in ARRDG did not affect the pharmacokinetics of sesamin.

Overexpression of various pro-inflammatory factors in microglial cells tends to induce neurodegenerative diseases, for which there is no effective therapy available. Aureonitol (1) and seven analogues, including six previously undescribed [elatumenol A-F (2-4, 6-8, respectively)], along with two new orsellinic acid esters [elatumone A and B (9 and 10)], were isolated from Chaetomium elatum. The structures of the compounds were established through comprehensive analysis of spectroscopic data, including high-resolution mass spectra and one- and two-dimensional NMR, and absolute configurations determined by the Mosher method, dimolybdenum tetraacetate-induced circular dichroism, and theoretical calculations including electronic circular dichroism and NMR. Metabolites 3, 4, 7, and 8 exhibited antineuroinflammatory activity by attenuating the production of inflammatory mediators, such as nitric oxide, interleukin-6, interleukin-1β, tumor necrosis factor-α, and reactive oxygen species. Western blot results indicated 8 decreases the level of inducible nitric oxide synthase and cyclooxygenase-2 and suppresses the expression of Toll-like receptor 4 and nuclear factor kappa-B (NF-κB) as well as the phosphorylation of the inhibitor of NF-κB and p38 mitogen-activated protein kinases in lipopolysaccharide-activated BV-2 microglial cells.

Sugarcane is an established industrial crop providing sugar, ethanol and biomass‐derived electricity worldwide. Cane sugar content is an important breeding target, but its improvement remains very slow in many breeding programmes. Biotechnology strategies to improve sucrose accumulation made little progress at the crop level, mainly due to the limited understanding of its regulation. miRNAs regulate many metabolic processes in plants. However, their roles and target genes associated with sugarcane sucrose accumulation remain unknown. Here, we conducted high‐throughput sequencing of transcriptome, small RNAs and degradome of leaves and stem of two early‐maturing sugarcane genotypes with contrasting sucrose content from the early to late stages of sucrose accumulation stages, which provided more insights into miRNA‐associated gene regulation during sucrose accumulation. The stem sucrose content in both genotypes increased steadily with time during sucrose accumulation stage. Transcriptome analysis identified 18,722 differentially expressed genes (DEGs) between both genotypes during sucrose accumulation. The major DEGs identified were involved in starch and sucrose metabolism, and photosynthesis. miRNA sequencing identified 563 known and 281 novel miRNAs from both genotypes during sucrose accumulation. Of these, 311 miRNAs were differentially expressed. A combined transcriptome and miRNA data analysis revealed differentially expressed miRNA‐target mRNA pairs related to sugar metabolism, of which 46 targets were transcription factors (TFs). miR172, miR164, miR396 and miR169 appear to regulate AP2/ERF, NAC, GRF and bZIP TF members associated with sugar metabolism. This is the first report of sugarcane miRNAs associated with sugar accumulation.

To explore alternative approaches to the CO2 reduction to formate and provide an insight into the spin state effect on the CO2 reduction, we theoretically designed a kind of low-valence iron(I) model complex, whose doublet, quartet, and sextet states are denoted as 2Fe(I), 4Fe(I), and 6Fe(I), respectively. This complex is featured with an iron(I) center, which bonds to a 1,2-ethanediamine (en) and a 2-hydroxy-biphenyl group. Reaction mechanisms for the CO2 reduction to formate catalyzed by this iron(I) model complex were explored using density functional theory (DFT) computations. Studies showed that the univalent iron(I) compound can efficiently fix and activate a CO2 molecule, whereas its oxidized forms with trivalent iron(III) or bivalent iron(II) cannot activate CO2. For the iron(I) compound, it was found that the lowest spin state 2Fe(I) is the most favorable for the CO2 reduction as the reactions barriers involving 2Fe(I), 4Fe(I), and 6Fe(I) are 25.6, 37.2, and 35.9 kcal/mol, respectively. Yet, a photosensitizer-free visible-light-mediated high–low spin shift from 4Fe(I) and 6Fe(I) to 2Fe(I) is likely through the reverse intersystem crossing (RIC) because the 4Fe(I) and 6Fe(I) compounds have strong absorption in the visible-light range. Notably, the synergistic interaction between the hydrogen bonding from the auxiliary hydroxyl group in the 2-hydroxy-biphenyl moiety to CO2 and an intermediate five-membered ring promotes the proton transfer, leading to the formation of the −COOH moiety from CO2 and the Fe–O bond. With the addition of H2, one H2 molecule is split by the Fe–O bond and thus serves as H atom sources for both the CO2 reduction and the recovery of the auxiliary hydroxyl group. The present theoretical study provides a novel solution for the challenging CO2 reduction, which calls for further experimental verifications.

The residue and dissipation dynamics of cyazofamid and its main metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) in garlic, garlic bolt and garlic sprouts were investigated by QuEChERS ...

Carbonatite-related rare earth element (REE) deposits are major hosts of REE resources. REE mineralization in these deposits is generally associated with hydrothermal systems at late stages of carbonatite evolution, but the nature of ore-forming fluids and their role in concentrating REEs are not well understood. In this study, we quantified the nature of ore-forming fluids by conducting a detailed investigation on the fluid inclusions of the Dalucao carbonatite–related REE deposit, Southwest China. Based on the phases present at room temperature, three types of fluid inclusions, namely, high-density, CO2-rich inclusions, solid-bearing brine inclusions, and aqueous liquid inclusions, have been distinguished in the deposit. High-resolution Raman mapping reveals that the daughter minerals in the earliest brine inclusions are dominantly composed of sulfate (average mass proportion of 92.3%) with minor chloride (3.1%), carbonate (4.4%), and silicate (0.2%). In addition, a Raman peak of SO42– has been detected in the liquid phase of the aqueous inclusions. These new results suggest that the early, high-temperature ore-forming fluids are unique for containing extremely high concentrations of sulfate. Such sulfate-rich fluids are confirmed to be responsible for transporting appreciable amounts of REEs in the forms of REE-sulfate complexes. We further propose that deposition of REE minerals was mainly triggered by decreasing temperatures, which, as a result, reduced the solubility of sulfate in the fluids. Our new findings highlight the fact that sulfate-rich fluids tend to be more common in carbonatite-related REE deposits and play key roles in REE mineralization.

γ-Aminobutyric acid (GABA) is a non-protein amino acid involved in regulating various environmental adaption in plants. Twenty-six-day-old creeping bentgrass plants were treated with or without GABA (0.5 mM) and then exposed to heat stress (35/30 °C, day/night) for 25 days. Results showed that exogenous GABA application significantly increased endogenous GABA accumulation and alleviated heat-caused growth inhibition and water loss during heat stress. GABA-treated creeping bentgrass maintained significantly lower carbonyl content, malondialdehyde content, and electrolyte leakage, but exhibited higher total antioxidant capacity and antioxidant enzyme activities (SOD, CAT, POD, APX, and DR) than untreated plants under heat stress. Heat stress significantly decreased chlorophyll content, stomatal conductance, transpiration rate, net photosynthesis, and water use efficiency. However, GABA application effectively alleviated these heat-induced negative effects in creeping bentgrass. In addition, exogenous GABA further increased the expression of heat-induced HSPs (HSP12, HSP17.8, HSP26.7, HSP70, HSP82, HSP90.1-A1, HSP90.1-B1, and HSP90-5) and HSFs (HSFA-2c, HSFA-2d, HSFA-6a, HSFB-2b, and HSFC-2b) and also further increased the abundance of HSP70, HSP90-1, and HSP101 in leaves of creeping bentgrass under heat stress. These results indicated that GABA alleviated heat-induced oxidative damage and chlorophyll loss through enhancing antioxidant capacity. GABA-treated creeping bentgrass maintained higher photosynthesis in leaves contributing to higher accumulation of water soluble carbohydrates for osmotic balance and energy supply under heat stress. GABA-regulated thermotolerance could be involved in upregulating HSF pathways in creeping bentgrass.

Recently, stretchable and wearable health monitoring equipment has greatly improved human’s daily life, which sets higher demands for portable power source in stretchability, sustainability, and biocompatibility. In this work, we proposed a stretchable triboelectric nanogenerator (TENG) based on stretchable poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/porous carbon hybrid for oxyhemoglobin saturation (SpO2) monitoring. To combine advantages of carbon material for its high conductivity and organic electrode for its high stretchability, we spin-coated a solution of PEDOT:PSS/porous carbon onto a plasma-treated pre-stretched Ecoflex film to fabricate a stretchable electrode with rough surface. Due to its roughness and high potential difference with the dielectric material, the stretchable-electrode-based TENG exhibited better performance compared to the pristine TENG based on carbon or PEDOT:PSS material. The output voltage and current reached up to 51.5 V and 13.2 µA as the carbon concentration increased. More importantly, the performance further increased under large strain (100%) which is suitable for wearable systems. Finally, the device demonstrated its application potential for powering a flexible blood oxygen monitor. This simple and cost-effective method can enhance the stretchability and stability of organic/inorganic electrode-based TENG, which paves the development of high-performance stretchable TENG.

There has been growing interest in the CO2 capture and reduction by transition-metal-free catalysts. Here we performed a proof-of-concept study using an ab initio valence bond method called the block-localized wave function (BLW) method. The integrated BLW and density function theory (DFT) computations demonstrated that heterobimetallic Ae+/Al(I) (Ae represents alkaline earth metals Mg and Ca) Lewis acid/base combinations without transition metals can facilely capture and activate CO2. There are two remarkable findings in this study. The first concerns the ionic nature of the metal-metal bonds. The experimentally synthesized low valent aluminum compound with a bidentate β-diketiminate (BDI) ligand, or (BDI)Al(I) in brief, is a Lewis base due to the lone pair on the aluminum cation though overall Al(I) is positively charged. Al(I) can form ionic metal-metal bonds with the alkaline earth metals of the positively charged Lewis acids (BDI)Ae+. This type of ionic metal-metal bonds is counterintuitive and antielectrostatic as both metals carry positive charges. The second finding is the CO2 activation mechanism. (BDI)Al(I) can effectively bind and activate CO2 by transferring one electron to CO2, and the resulting complex can be best expressed as [(BDI)Al(I)]+[CO2]-. The participation of (BDI)Ae+ further enhances the capture and activation of CO2 by (BDI)Al(I).

Although chirality is an ever-present characteristic in biology and some artificial molecules, controlling the chirality and demystifying the chirality origin of complex assemblies remain challenging. Herein, we report two homochiral Ag14 nanoclusters with inherent chirality originated from identical rotation of six square faces on a Ag8 cube driven by intra-cluster π···π stacking interaction between pntp− (Hpntp = p-nitrothiophenol) ligands. The spontaneous resolution of the racemic (SD/rac-Ag14a) to homochiral nanoclusters (SD/L-Ag14 and SD/R-Ag14) can be realized by re-crystallizing SD/rac-Ag14a in acetonitrile, which promotes the homochiral crystallization in solid state by forming C–H···O/N hydrogen bonds with nitro oxygen atoms in pntp− or aromatic hydrogen atoms in dpph (dpph = 1,6-bis(diphenylphosphino)hexane) on Ag14 nanocluster. This work not only provides strategic guidance for the syntheses of chiral silver nanoclusters in an all-achiral environment, but also deciphers the origin of chirality at molecular level by identifying the special effects of intra- and inter-cluster supramolecular interactions., The preparation of chiral monolayer-protected metal clusters is interesting for their potential applications in a variety of fields, including catalysis. Here, the authors synthesize chiral Ag14 nanoclusters in an all-achiral environment, and decipher the origin of chirality at the molecular level; the solvent choice is key to achieve homochiral crystallization.

S-adenosylmethionine decarboxylase (SAMDC) mediates the biosynthesis of polyamines (PAs) and plays a positive role in plants’ response to adversity stress tolerance. In this study, we isolated a SAMDC gene from white clover, which is located in mitochondria. It was strongly induced when white clover exposed to drought (15% PEG6000), salinity (200 mM NaCl), 20 μM spermidine, 100 μM abscisic acid, and 10 mM H2O2, especially in leaves. The INVSc1 yeast introduced with TrSAMDC1 had tolerance to drought, salt, and oxidative stress. Overexpression of TrSAMDC1 in Arabidopsis showed higher fresh weight and dry weight under drought and salt treatment and without growth inhibition under normal conditions. Leaf senescence induced by drought and saline was further delayed in transgenic plants, regardless of cultivation in 1/2 MS medium and soil. During drought and salt stress, transgenic plants exhibited a significant increase in relative water content, maximum photosynthesis efficiency (Fv/Fm), performance index on the absorption basis (PIABS), activities of antioxidant protective enzymes such as SOD, POD, CAT, and APX, and a significant decrease in accumulation of MDA and H2O2 as compared to the WT. The concentrations of total PAs, putrescine, spermidine, and spermidine in transgenic lines were higher in transgenic plants than in WT under normal and drought conditions. These results suggested that TrSAMDC1 could effectively mitigate abiotic stresses without the expense of production and be a potential candidate gene for improving the drought and salt resistance of crops.

As a natural sesquiterpene compound with numerous biological activities, patchoulol has extensive applications in the cosmetic industry and potential usage in pharmaceuticals. Although several patchoulol-producing microbial strains have been constructed, the low productivity still hampers large-scale fermentation. Escherichia coli possesses the ease of genetic manipulation and simple nutritional requirements and does not comprise competing pathways for the farnesyl diphosphate (FPP) precursor, showing its potential for patchoulol biosynthesis. Here, combinatorial strategies were applied to produce patchoulol in E. coli. The initial strain was constructed, and it produced 14 mg/L patchoulol after fermentation optimization. Patchoulol synthase (PTS) was engineered by semirational design, resulting in improved substrate binding affinity and a patchoulol titer of 40.3 mg/L; the patchoulol titer reached 66.2 mg/L after fusing of PTS with FPP synthase. To further improve the patchoulol production, the genome of an efficient chassis strain was engineered by deleting the competitive routes for acetate, lactate, ethanol, and succinate synthesis and cumulatively enhancing the expression of efflux transporters, which improved patchoulol production to 338.6 mg/L. When tested in a bioreactor, the patchoulol titer and productivity were further improved to 970.1 mg/L and 199 mg/L/d, respectively, and were among the highest levels reported using mineral salt medium.

The reaction behaviors of primary volatiles from oil shale pyrolysis were investigated using a two-stage reactor under different in-situ thermal reaction conditions. The reaction parameters of secondary reactor, such as, reactor temperature, atmosphere and residence time, were studied for their effects on the pyrolysis oil/gas yield and quality. The results showed that the reaction temperature had profound influence on the oil and gas yield. The pyrolyzed shale oil and gas yield reduced by 15% and increased by 20% (mass) respectively, with the temperature of 2nd stage reactor increasing from 600 to 650°C under optimized reaction condition of 1st stage. Comparing with nitrogen atmosphere, the liquid oil yield could be enhanced by 5% when steam was added as the reaction atmosphere in the second stage, and the corresponding oil was mainly concentrated in the gasoline and diesel distillations (that is, boiling point

Hot compression deformation behavior of the Cu-0.45Cr-1.0Ni-0.28Si-0.14Co alloy was studied by a thermal-mechanical simulator at strain rates of 0.001–1 s−1 and deformation temperatures of 700–900°C. The microstructure and texture of the copper alloy after the hot compression deformation were investigated. The results showed that the flow behavior of the Cu-Cr-Ni-Si-Co alloy was significantly affected by the deformation temperature and strain rate. The typical dynamic recrystallization (DRX) occurred at high temperatures and low strain rates, while the typical dynamic recovery (DRV) appeared at low temperatures and high strain rates. When the deformation temperature increased from 700°C to 900°C, a transition from copper and S texture to gross texture was found. The value of hot deformation activation energy (Q) was calculated as 330.87 kJ/mol. The optimized hot deformation parameters for the Cu-Cr-Ni-Si-Co alloy were 800–850°C/0.01–0.1 s−1.

In this paper, the contact interface between FGH96 superalloy melts and refractory slurry with corundum powder and silica sol at 1600°C with different soaking time in 10-240 min range was investigated. The morphology and composition of the contact interface were studied by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that the reaction layer formed on the contact interface between the melting superalloy and the refractory slurry, and is mainly consist of Alumina and contains a small amount of other metal elements such as Ti and Cr. The reaction layer was not smooth on the micro level, and there was a peninsula-like structure protruding into the internal part of the melting superalloy on the reaction zone, and even started to fall off at some places to form islands. With the increase of soaking time, the reaction between melt of superalloy and refractory slurry increased gradually and the reaction layer began to combine with the refractory slurry substrate and form obvious interaction layered structure, resulting in the corrosion of refractory slurry substrate. With the soaking time over 120 min, the stable contact interface was destroyed. Thermodynamic calculation shows that the substitution reaction between Al in superalloy and SiO2 in refractory slurry meets the thermodynamic conditions, and the reaction can proceed forward.

To reduce the agglomeration of graphene and enhance the interface bonding between reduced graphene oxide (RGO) and copper substrate, copper plating on the graphene surface was prepared by the in-situ reduction method. To improve the strength of the copper matrix, the microalloying strategy of adding titanium to the matrix was adopted. By changing the mass fraction of titanium in the matrix, the optimum ratio of RGO was obtained( Ti mass fraction was 5:1), and the tensile strength was maximized. The results show that RGO did not agglomerate obviously in the matrix. At the same time, the composite powder could be densified rapidly by spark plasma sintering (SPS), which could effectively protect the original distribution of the additive phase in the matrix. In this paper, Cu@RGO/Cu-Ti was prepared and the strengthening mechanism of the composites discussed, providing a new insights into the interface design and carbide formation mechanism of advanced graphene/copper composites with high mechanical properties.

High-temperature tribology, which is often involved during hot metal forming, is controlled via oxidation on a rubbing surface. However, for high chromium stainless steel (ST), where oxidation is strongly inhibited, the effect of counterface materials on tribological behavior is yet to be elucidated. In this study, the effects of counterfaces on the tribological behavior of 253MA ST and mild steel (MS) are investigated via a ball-on-disc test at 900 °C using a 20 N load. The results reveal that high-speed steel (HSS) experiences severe abrasive wear with MS and causes severe sticking problems with ST. Si3N4 and SiC present substantially stronger abrasive wear resistance than HSS with MS, and the friction coefficients are dependent on the type of ceramic. Both ceramics can facilitate the establishment of a thick tribo-oxide layer (> 3 µm) on ST to prevent sticking; however, this is accompanied by severe pull-out and fracture wear. The effects of the counterface on the mechanical properties of the tribo-oxide layer, near-surface transformation, and the responses of the tribo-oxide layer to friction and wear are discussed. This study contributes to the understanding of interfacial tribological behaviors when different types of tools are used on MS and ST.

Member domain 3 (LRIG3) of the LRIG gene family is down-regulated in several cancers. However, its role in bone marrow mesenchymal stem cells (BMSCs) in gliomas and the related mechanisms is unknown. The qRT-PCR assessed LRIG3 mRNA level. Rat BMSCs were randomly assigned into glioma group (BMSCs cultured in glioma microenvironment); LRIG3 overexpression group; and si-LRIG3 inhibitor group followed by analysis of LRIG3 expression, cell proliferation, PCNA and Ki-67 apoptosis, TNF-α; and HIF-1α/VEGF mRNA level. LRIG3 mRNA expression was decreased in gliomas patients (P < 0.05). BMSCs cultured in glioma microenvironment showed decreased LRIG3, increased cell proliferation, decreased PCNA, Ki-67 and TNF-α secretion as well as elevated HIF-1α and VEGF level (P < 0.05). Transfection of LRIG3 siRNA further promoted the above changes. Conversely, LRIG3 plasmid transfection significantly promoted its expression in glioma BMSCs (P < 0.05), inhibited cell proliferation, promoted PCNA, Ki-67, and TNF-α secretion, and increased HIF-1α and VEGF level (P < 0.05). LRIG3 in rat BMSCs cultured in the glioma microenvironment is decreased. Down-regulation of LRIG3 inhibits TNF-α secretion by activating HIF-1α/VEGF pathway regulating BMSCs proliferation and apoptosis.

Background After storing blood for a period of time, the structure and properties of the red blood cells (RBC) will change, which results in a decrease in the oxygen-carrying capacity, and further has a certain impact on their exosomes. Objectives Effective oxygen uptake (Q), P50, 2,3-DPG, and Na+-K+-ATP of RBC after different storage times were detected. Electron microscopy was used to observe the morphology of RBC and the characteristics of secreting exosomes. Western blot was used to detect the expression of phenotypes CD63 and CD81 of exosomes, and the expression of mitochondrial riboprotein MRPS35 of exosomes was also detected to explore the mechanism of decreased function of RBC with the extension of preservation time. Material and methods After the RBC suspension was prepared, the effective oxygen-carrying capacity (Q) and P50, as well as 2,3-DPG and Na+-K+-ATP were prepared. This was followed by morphology observation of erythrocyte exosomes using transmission electron microscope (TEM), and by western blot analysis of exosome phenotypes CD63 and CD81. Results Erythrocytes secrete exosomes, which results in abnormal expression of related proteins in mitochondria. This leads to increased ROS production, mitochondrial apoptosis and, finally, changes in or damage to erythrocytes. Conclusions Changes in the rheological properties and oxygen-carrying functions of erythrocytes during preservation are all observable manifestations, and underlying these manifestations are mechanisms of damage to erythrocytes at a molecular level. Erythrocytes secrete exosomes, which results in abnormal expression of related proteins in mitochondria, increasing ROS production, mitochondrial apoptosis and, finally, changes or damage to erythrocytes.

A zirconium-based metal-organic framework (MOF) was successfully constructed via solvothermal assembly of a triphenylamine-based tricarboxylate ligand and Zr(IV) salt, the structure simulation of which revealed that it possesses a two-dimensional layered framework with a relatively rare dodecnuclear Zr12 cluster as the inorganic building unit. The inherent photo-responsive property derived from the incorporated photochromic triphenylamine groups combined with its high stability makes the constructed MOF an efficient heterogeneous photocatalyst for the oxidation of sulfides, which is a fundamentally important reaction type in both environmental and pharmaceutical industries. The photocatalytic activity of the constructed MOF was first investigated under various conditions with thioanisole as a representative sulfide substrate. The MOF exhibited both high efficiency and selectivity on aerobic oxidation of thioanisole in methanol utilizing molecular oxygen in air as the oxidant under blue light irradiation for 10 h. Its high photocatalytic performance was also observed when extending the sulfide substrate to diverse thioanisole derivatives and even a sulfur-containing nerve agent simulant (2-chloroethyl ethyl sulfide). The high photocatalytic efficiency and selectivity to a broad set of sulfide substrates make the triphenylamine-incorporating zirconium-based MOF a highly promising heterogeneous photocatalyst. Ministry of Education (MOE) This work was supported by the "Qilu Young Talent Scholar" program of Shandong University and the Singapore Academic Research Fund (RT12/19).

The corrosion behavior of a copper-based shape memory alloy (Cu−Al−Mn−Zn−Zr) in 3.5 wt.% NaCl solution was investigated by means of potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). At the beginning of corrosion, oxidation products formed on the surface of the shape memory alloy and constantly covered the reaction surface, resulting in the decrease of corrosion rate. After 4 d of immersion in NaCl solution, the corrosion product layer became thick and porous, leading to the increase of corrosion rate, and the corrosion reaction mechanism changed from polarization control to diffusion control. The diffusion impedance increased with increasing thickness of the oxide layer for the samples immersed in NaCl solution for 6−15 d. During the whole corrosion process, the reaction mechanism of the alloy changed and the corrosion resistance was improved continuously. The corrosion products mainly contained CuO, ZnO, Al2O3, MnO/Mn2O3, MnO2 and Al(OH)3. Transition of the corrosion products from Cu2O to CuO and Al2O3 to Al(OH)3 occurred during corrosion.

The oxidation of aldehydes is an efficient methodology for the synthesis of carboxylic acids. Herein we hope to report a simple, efficient and recyclable protocol for aerobic oxidation of aldehydes to carboxylic acid by using C3N4supported silver nanoparticles (Ag/3N4) as a catalyst in aqueous solution under mild conditions. Under standard conditions, the corresponding carboxylic acids can be obtained in good to excellent yields. In addition, Ag/C3N4 is convenient for recovery and could be reused three times with satisfactory yields.

The corrosion behavior of imitation-gold Cu-Zn-Ni-Sn alloys with and without Al was investigated by means of color difference testing, static corrosion measurements, scanning electron microscopy analysis, electrochemical impedance measurements, and x-ray photoelectron spectroscopy analysis. The results showed that aluminum inhibited dissolution of Zn and Sn by the formation of an oxide film on the surface of the Cu-Zn-Ni-Sn alloy during corrosion, effectively improving its corrosion resistance. A transition of the corrosion product from Cu2O and Cu(OH)2 to CuO occurred on the surface of Cu-Zn-Ni-Sn-Al alloy, and the corrosion rate of the alloy decreased with increasing corrosion time due to the formation of the oxidation film and the hydrophobic effect of Zn5(CO3)2(OH)6 in the product layer.

As a potential renewable and nitrogen-rich resource, millions of tons of feather waste are generated from poultry farming and this has been steadily increasing. Bioconversion is the most promising low-cost and environmentally benign recycling method, while the efficiency of the isolated natural feather degrading bacteria (FDB) cannot satisfy the requirements of industrial utilization. The process of bacterial degradation of feathers not only requires proteases but also involves complex reduction mechanisms that have not yet been revealed. Previous heterologous expression of keratinase genes in non-FDB hosts achieved only very limited success. In this study, the mechanism of sulfite production via cysteine dioxygenase (CDO1) oxidation was first identified in Streptomyces sp. SCUT-3, which is important for feather disulfide bond reduction. The knockdown of cdo1 significantly decreased the sulfite production (from 38.5 to 22.5 mg L−1) and feather degradation rate (from 45.7% to 39.5%) of SCUT-3 in 5% chicken feather medium (CFM) culture. The overexpression of cdo1 increased bacterial single-cell sulfite production and feather protein conversion efficiency by 3.8 and 2.5 fold, respectively, on day 2 in 5% CFM. On this basis, a new strategy is proposed for increasing feather degradation efficiency by enhancing the reducing power and keratinase activity of FDB according to their own feather degradation mechanism. Thus, the co-overexpression of CDO1 and protease Sep39 successfully increased SCUT-3's feather protein conversion efficiency (42.5% higher than the wild-type) on day 2 in 5% CFM culture. With the co-overexpression strain SCUT-Ocdo1-sep39, 57.5% of proteins in feathers were converted to soluble peptides and free amino acids (0.20 g and 0.29 g g−1 feather, respectively) by solid-state fermentation in 6 d, which was 28.6% higher than that obtained for wild-type SCUT-3. The method developed herein exhibits a much higher economic benefit and a lower ecological footprint than previously reported feather-processing methods and is powerful for industrial recycling of feather waste. This study also elucidates FDB's disulfide bond mechanism and provides a reference for further genetic modification of FDB.

In industry, L-alanine is biosynthesized using fermentation methods or catalyzed from L-aspartic acid by aspartate β-decarboxylase (ASD). In this study, a triple-enzyme system was developed to biosynthesize L-alanine from cis-butenedioic anhydride, which was cost-efficient and could overcome the shortcomings of fermentation. Maleic acid formed by cis-butenedioic anhydride dissolving in water was transformed to L-alanine via fumaric acid and L-asparagic acid catalyzed by maleate isomerase (MaiA), aspartase (AspA) and ASD, respectively. The enzymatic properties of ASD from different origins were investigated and compared, as ASD was the key enzyme of the triple-enzyme cascade. Based on cofactor dependence and cooperation with the other two enzymes, a suitable ASD was chosen. Two of the three enzymes, MaiA and ASD, were recombinant enzymes cloned into a dual-promoter plasmid for overexpression; another enzyme, AspA, was the genomic enzyme of the host cell, in which AspA was enhanced by a T7 promoter. Two fumarases in the host cell genome were deleted to improve the utilization of the intermediate fumaric acid. The conversion of whole-cell catalysis achieved 94.9% in 6 h, and the productivity given in our system was 28.2 g (L h)−1, which was higher than the productivity that had been reported. A catalysis-extraction circulation process for the synthesis of L-alanine was established based on high-density fermentation, and the wastewater generated by this process was less than 34% of that by the fermentation process. Our results not only established a new green manufacturing process for L-alanine production from cis-butenedioic anhydride but also provided a promising strategy that could consider both catalytic ability and cell growth burden for multi-enzyme cascade catalysis.

The low carbon content powder metallurgy (PM) 625 alloy were manufactured by vacuum induction gas atomization (VIGA) and hot isostatically pressing (HIP) for marine-based application such as parts in the subsea Xmas tree. Corrosion experiment was performed in simulated deep seawater and subsea oil & gas service environment. The microstructures and properties of low carbon 625 alloy were comparably investigated with that of the as-cast alloy. The results indicated that the dendritic arm spacing (DAS) of the as-cast 625 alloy is 2 orders of magnitude higher than that of the powders, whereas the HIPed alloys possess a fine equiaxed grain structures without dendritic segregation and an average grain size of 14.5μm. No minor phase has been found beside the γ matrix in the original powders with different particle size. The tensile strength of low carbon PM 625 alloy is 26% higher than that of as-cast 625 alloy. PM 625 alloy possesses an excellent corrosion resistant in simulated deep seawater and oil & gas service environment for 30 days.

Metal-stabilized radicals have been increasingly exploited in modern organic synthesis. Here, we theoretically designed a metalloradical complex Co-C˙Ph3 with the triplet characters through the transition metal cobalt (Co0) coordinating a triphenylmethyl radical. The potential catalytic role of this novel metalloradical in the CO2 reduction with H2/CH4 in the gas phase was explored via density functional theory (DFT) calculations. For the CO2 reduction reaction with H2, there are two possible pathways: one (path A) is the activation of CO2 by Co-C˙Ph3, followed by the hydrogenation of CO2. The other (path B) starts from the splitting of the H-H bond by Co-C˙Ph3, leading to the transition-metal hydride complex CoH-H, which can reduce CO2. DFT computations show that path B is more favorable than path A as their rate-determining free energy barriers are 18.3 and 27.2 kcal mol-1, respectively. However, for the reduction of CO2 by CH4 two different products, CH3COOH and HCOOCH3, can be generated following different reaction routes. Both routes begin with one CH4 molecule approaching the metalloradical Co-C˙Ph3 to form the intermediate CoH-CH3. This intermediate can evolve following two different pathways, depending on whether the H bonded to Co is transferred to the O (pathway PO) or the C (pathway PC) of CO2. Comparing their rate-determining steps, we identified that the PO route is more favorable for the reduction of CO2 by CH4 to CH3COOH with the reaction barrier 24.5 kcal mol-1. Thus, the present Co0-based metalloradical system represents a viable catalytic protocol that can contribute to the effective utilization of small molecules (H2 and CH4) to reduce CO2, and provides an alternative strategy for the exploration of CO2 conversion.

PURPOSE This experiment was conducted to investigate the dielectric properties of different types of thyroid nodules. Our goal was to find a simple and fast method to detect thyroid diseases at different stages from the dielectric properties of thyroid nodules. METHODS We used the open-ended coaxial line method to measure the dielectric permittivities of thyroid tissues from 155 patients at frequencies ranging from 1 to 4000 MHz. Tissues that were investigated included normal thyroid tissue and benign and malignant thyroid nodules (nodular goiter, follicular adenoma, papillary carcinoma, and follicular carcinoma), as determined from pathological reports. Differences in dielectric properties were measured between each nodule and the surrounding 1 cm of tissue. RESULTS The analysis results revealed that the dielectric permittivity and conductivity values were positively correlated with the degree of malignancy of the nodule (normal

Carrier mobility (weighted mobility more specifically) of thermoelectrics fundamentally determines its power factor, representing a new cut-in point to optimize the thermoelectric performance. However, researches on enhancing the carrier mobility to improve power factor has been overlooked. In present work, we highlight a significant mobility enhancement in BiTeI by introducing I deficiency, which improves the power factor and final ZT value. A defect compensation weakening mechanism is adopted that the induced I vacancies reduce the concentration of intrinsic I Te • and Te I ' antisite defects, which weakens the donor-acceptor defect compensation and suppresses the defects-induced carrier scattering. As a result, the carrier mobility is obviously enhanced in I-deficient samples, which ensures an effectively improved power factor and final ZT. A maximum ZT of 0.57 is achieved at 570 K perpendicular to the pressing direction, which is superior to pristine BiTeI and among the highest values reported for bulk BiTeI-based thermoelectric materials. Present work opens up a new avenue for thermoelectric optimization mainly by mobility enhancement.

In this study, the purification and characterization of a novel polysaccharide-based bioflocculant BM2 produced by a bacterium Bacillus megaterium strain PL8 with self-flocculating property were investigated. The results showed that BM2 was an acidic polysaccharide composed of Gal, GalUA, Glc, GlcUA and Man at a molar ratio of 45.1: 33.8:9.3:9.2:2.4, respectively. The molecular weight of BM2 was 4.55 × 106 Da. BM2 had high flocculation efficiencies across a wide pH ranged from 4 to 11 and a wide temperature ranged from 20 to 100 °C towards kaolin clay. BM2 was a cation-independent bioflocculant which could achieve high flocculation activity without the addition of other cations. Adsorption bridging was the main mechanism in the flocculation process of BM2 towards kaolin clay. The BM2 also displayed a high removal efficiency in terms of Congo red (88.14%) and Pb2+ ions (82.64%). These results suggested that BM2 had a great potential as an efficient bioflocculant candidate in wastewater treatment.

Background Chitosan (CTS), a natural polysaccharide, exhibits multiple functions of stress adaptation regulation in plants. However, effects and mechanism of CTS on alleviating salt stress damage are still not fully understood. Objectives of this study were to investigate the function of CTS on improving salt tolerance associated with metabolic balance, polyamine (PAs) accumulation, and Na+ transport in creeping bentgrass (Agrostis stolonifera). Results CTS pretreatment significantly alleviated declines in relative water content, photosynthesis, photochemical efficiency, and water use efficiency in leaves under salt stress. Exogenous CTS increased endogenous PAs accumulation, antioxidant enzyme (SOD, POD, and CAT) activities, and sucrose accumulation and metabolism through the activation of sucrose synthase and pyruvate kinase activities, and inhibition of invertase activity. The CTS also improved total amino acids, glutamic acid, and γ-aminobutyric acid (GABA) accumulation. In addition, CTS-pretreated plants exhibited significantly higher Na+ content in roots and lower Na+ accumulation in leaves then untreated plants in response to salt stress. However, CTS had no significant effects on K+/Na+ ratio. Importantly, CTS enhanced salt overly sensitive (SOS) pathways and also up-regulated the expression of AsHKT1 and genes (AsNHX4, AsNHX5, and AsNHX6) encoding Na+/H+ exchangers under salt stress. Conclusions The application of CTS increased antioxidant enzyme activities, thereby reducing oxidative damage to roots and leaves. CTS-induced increases in sucrose and GABA accumulation and metabolism played important roles in osmotic adjustment and energy metabolism during salt stress. The CTS also enhanced SOS pathway associated with Na+ excretion from cytosol into rhizosphere, increased AsHKT1 expression inhibiting Na+ transport to the photosynthetic tissues, and also up-regulated the expression of AsNHX4, AsNHX5, and AsNHX6 promoting the capacity of Na+ compartmentalization in roots and leaves under salt stress. In addition, CTS-induced PAs accumulation could be an important regulatory mechanism contributing to enhanced salt tolerance. These findings reveal new functions of CTS on regulating Na+ transport, enhancing sugars and amino acids metabolism for osmotic adjustment and energy supply, and increasing PAs accumulation when creeping bentgrass responds to salt stress.

A sensitive, effective, and reliable method for the accurate determination of fipronil and four metabolites (fipronil carboxamide, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl) in foodstuffs of animal origin (egg, milk, beef kidney, beef liver, chicken, and chicken liver) was developed by isotope dilution–gas chromatography–negative chemical ionization–tandem mass spectrometry (GC–NCI–MS/MS). Samples were purified by a modified QuEChERS method. Four isotopically labeled internal standards were added in the sample extraction process to compensate for the matrix effect. The average recoveries were 78.2–107.1% with RSD ≤ 8.5%. The limits of quantification (LOQs) were 0.2 μg kg−1 for fipronil carboxamide and fipronil sulfone and 0.1 μg kg−1 for fipronil, fipronil sulfide, and fipronil desulfinyl. At the same time, the fragmentation mechanism of the five target compounds was analyzed via mass spectral data to help identify the compounds.

The addition of heavy protein to aquafeed causes low digestibility, high cost and significant nitrogen pollution in the water. The addition of protease is an effective way of improving protein absorption, but few proteases have been developed specifically for aquafeeds. The hydrolysis efficiency of protease additives for plant protein in the neutral gut environment and their synergy with endogenous proteases has not been sufficiently investigated. In this study, the performance of the recombinant neutral protease rNpI as an aquafeed additive to reduce the raw protein materials in the diet of Carassius carassius during 56 days of growth was evaluated. rNpI effectively hydrolysed soya bean protein isolates (SPI) with a high degree of hydrolysation and a high small‐peptide yield. The rNpI‐treated SPI exhibited a notable antioxidant activity, which benefited fish health. In vitro digestibility indicated that rNpI complemented trypsin in SPI digestion better than papain or Alcalase. The growth trial showed that the addition of rNpI could warrant a reduction in the crude protein and gross energy of feed while producing a lower feed‐conversion rate (FCR) and better growth performance. Crucian that were fed an RM‐wheat‐E diet (5.5% rapeseed meal and 5% wheat reduction) showed the best performance, with the lowest FCR and highest weight gain. These results indicate that rNpI could be an effective additive for the aquafeed industry and could provide economic benefits by reducing aquafeed protein requirements and nitrogen emissions. This study provides novel information and strategies for additive protease use and development in aquafeed.

Heat stress decreases crop growth and yield worldwide. Spermidine (Spd) is a small aliphatic amine and acts as a ubiquitous regulator for plant growth, development and stress tolerance. Objectives of this study were to determine effects of exogenous Spd on changes in endogenous polyamine (PA) and γ-aminobutyric acid (GABA) metabolism, oxidative damage, senescence and heat shock protein (HSP) expression in white clover subjected to heat stress. Physiological and molecular methods, including colorimetric assay, high performance liquid chromatography and qRT-PCR, were applied. Results showed that exogenous Spd significantly alleviated heat-induced stress damage. Application of Spd not only increased endogenous putrescine, Spd, spermine and total PA accumulation, but also accelerated PA oxidation and improved glutamic acid decarboxylase activity, leading to GABA accumulation in leaves under heat stress. The Spd-pretreated white clover maintained a significantly higher chlorophyll (Chl) content than untreated plants under heat stress, which could be related to the roles of Spd in up-regulating genes encoding Chl synthesis (PBGD and Mg-CHT) and maintaining reduced Chl degradation (PaO and CHLASE) during heat stress. In addition, Spd up-regulated HSP70, HSP70B and HSP70-5 expression, which might function in stabilizing denatured proteins and helping proteins to folding correctly in white clover under high temperature stress. In summary, exogenous Spd treatment improves the heat tolerance of white clover by altering endogenous PA and GABA content and metabolism, enhancing the antioxidant system and HSP expression and slowing leaf senescence related to an increase in Chl biosynthesis and a decrease in Chl degradation during heat stress.

Introduction Highly sensitive semiconductor gas sensors hold great potential for applications in trace gas detection. Reliable detection of ppb-level NO2 is crucial for environmental monitoring, which however still remains a challenge. In this work, we adopted a one-pot encapsulation strategy for synthesizing indium-doped ZnO porous hollow cages. In(acac)3 was selected as the indium source due to its molecular diameter between the cavity size (11.6 Å) and the aperture size (3.4 Å) of ZIF-8. During the crystallization progress of ZIF-8, it was in situ trapped in the cavities and In(acac)3@ZIF-8 composites were formed (Scheme a, b). During calcination, metal ion species, composed of In(acac)3@ZIF-8, were oxidized, leading to the formation of In-doped ZnO porous hollow cages (Scheme c, d). In this case, ZIF-8 served as the host backbone for the uniform distribution of the indium source as well as the production of porous hollow structure. In doping led to significantly enhanced NO2-sensing performance, achieving a response of 3.7 to 10 ppb of NO2, a high sensitivity of 187.9 ppm-1, and a limit of detection as low as 0.2 ppb. The mechanism of enhanced NO2-sensing properties was discussed in the terms of the intrinsic excellent gas accessibility of porous hollow structure and electronic sensitization by In doping. Our findings could be extended to design other porous doped ZnO oxides for high performance gas sensors and other applications. Method In(acac)3@ZIF-8 composites were synthesized by a one-pot encapsulation method. route. Briefly, 810 mg of Zinc nitrate hexahydrate and corresponding amounts of Indium(III) acetylacetonate were dissolved into 40 mL methanol to form precursor solutions. 40 mL of methanol solutions containing 721.6 mg of 2-methylimidazole were added into above solutions under stirring. The resulting solutions were stirred for 20 min and aged for 24 h at room temperature. After precipitation, obtained ZIF-8 derivatives were washed with methanol via centrifugation. The precipitates were further dried at 60 °C for 24 h and calcined at 500 °C for 2 h to obtain pristine and In-doped ZnO powders. The obtained samples are hereafter denoted as In/ZnO-X, where X represents the nominal In/Zn atomic ratio (multiplied by 100) used during the synthesis, e.g., In/ZnO-0 for un-doped ZnO, In/ZnO-2 for In/Zn of 2.0 at.%, In/ZnO-10 for In/Zn of 10.0 at.%. Results and Conclusions Figure 1a depicts dynamic electrical resistance changes of pristine and In-doped ZnO sensors in the presence of NO2 from 0.2 to 10 ppm at 300 °C. The sensors showed typical n-type semiconductor response behavior, the increase of electrical resistance in the presence of NO2. In addition, the electrical resistance increased with the increase of NO2 concentration for all the sensors, and at each concentration the increment of electrical resistance for In/ ZnO-10 was always much higher than that for other sensors. Further investigations on the performance of In/ZnO-10 in the NO2 concentration below 0.2 ppm were conducted. Figure 1b shows the dynamic response and recovery curves for the In/ZnO-10 sensor, which were measured by alternately exposing the sensor to ambient air and air/NO2 mixture at 300°C. The In/ZnO-10 sensor was effective for the detection of NO2 at 10, 25, 50, and 100 ppb, and a high response of 3.7 to 10 ppb of NO2 gas was obtained. And the calculated limit of detection was as low as 0.2 ppb, 2 orders of magnitude lower than that (23.4 ppb) of pristine ZnO. Therefore, the In/ZnO-10 sensor could be suitable for the detection of ppb-level NO2 put forward by the WHO for monitoring environmental pollution. Figure 1c exhibits the response of pristine and In-doped ZnO sensors as a function of NO2 concentration in the range below 1 ppm at 300 °C. The response value increased linearly with the increasing NO2 concentration, and the slope (i.e., sensitivity) also became larger with increasing In content. A large sensitivity of 187.9 ppm-1 was obtained for the In/ ZnO-10 sensor, 117.4, 9.5, and 9.1 times larger than that for pristine ZnO (1.6 ppm-1), In/ZnO-2 (19.8 ppm-1) and In/ZnO-6 (20.7 ppm-1), respectively. The wide linear dependence and high sensitivity of the In/ZnO-10 sensor are favorable for calibration and determination of the NO2 concentration in practical applications. Further tests at higher concentrations above 1 ppm showed the slope decreased with the increasing NO2 concentration, indicating the sensors were near saturation (Figure 1d). Nevertheless, the In/ZnO-10 sensor still possessed the highest response value and sensitivity among the sensors in the high-concentration range. References [1] Rajesh Kumar, O. Al-Dossary, Girish Kumar, Ahmad Umar, Zinc Oxide Nanostructures for NO2 Gas-Sensor Applications: A Review, Nano-Micro Lett. 7 (2015) 97-120. DOI: 10.1007/s40820-014-0023-3. [2] Lee, Jong-Heun, Gas Sensors using Hierarchical and Hollow Oxide Nanostructures: Overview. Sens. Actuators, B 140 (2009) 319-336. DOI: 10.1016/j.snb.2009.04.026. Figure 1

Summary Microbial sulfate reduction and sulfur oxidation are vital processes to enhance organic matter degradation in sediments. However, the diversity and composition of sulfate‐reducing bacteria (SRB) and sulfur‐oxidizing bacteria (SOB) and their environmental driving factors are still poorly understood in aquaculture ponds, which received mounting of organic matter. In this study, bacterial communities, SRB and SOB from sediments of aquaculture ponds with different sizes of grass carp (Ctenopharyngodon idellus) were analysed using high‐throughput sequencing and quantitative real‐time PCR (qPCR). The results indicated that microbial communities in aquaculture pond sediments of large juvenile fish showed the highest richness and abundance of SRB and SOB, potentially further enhancing microbial sulfur cycling. Specifically, SRB were dominated by Desulfobulbus and Desulfovibrio, whereas SOB were dominated by Dechloromonas and Leptothrix. Although large juvenile fish ponds had relatively lower concentrations of sulfur compounds (i.e. total sulfur, acid‐volatile sulfide and elemental sulfur) than those of larval fish ponds, more abundant SRB and SOB were found in the large juvenile fish ponds. Further redundancy analysis (RDA) and linear regression indicated that sulfur compounds and sediment suspension are the major environmental factors shaping the abundance and community structure of SRB and SOB in aquaculture pond sediments. Findings of this study expand our current understanding of microbial driving sulfur cycling in aquaculture ecosystems and also provide novel insights for ecological and green aquaculture managements., In aquaculture pond sediments, sulfate‐reducing bacteria (SRB) produced AVS through sulfate reduction, and sulfur‐oxidizing bacteria was especially important to reduce AVS. High concentrations of sulfur compounds (TS, AVS, and ES) could inhibit SRB and sulfate reduction. Disturbance to sediments by fish activities could enhance the sulfate reduction and sulfur oxidation in sediments.

Small molecules, including H2O2 and Ca, mediate stress signaling and drought tolerance in plants. The objective of this study was to determine whether improvement in drought tolerance by H2O2 and Ca were associated with the regulation of transcription factors and stress-protective genes in perennial grass species. Plants of creeping bentgrass (Agrostis stolonifera) were sprayed with water (control), H2O2 (9 mm), or CaCl2 (10 mm) and exposed to drought stress for 20 days in controlled-environment growth chambers. Foliar application of H2O2 or Ca led to significant improvement in drought tolerance of creeping bentgrass, as demonstrated by greater turf quality, leaf relative water content, chlorophyll content, photochemical efficiency, and cell membrane stability, as compared with the untreated control. The application of H2O2 and Ca resulted in significant up-regulation of genes in Ca signaling transduction pathways [Ca-dependent kinase 26 (CDPK26), mitogen-activated protein kinase 1 (MAPK1), and 14-3-3] and transcript factors (WRKY75 and MYB13). For genes encoding antioxidant enzymes, H2O2 mainly enhanced superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) expression, while Ca primarily improved transcript levels of SOD, monodehydroascorbate reductase (MDHAR), and GR. In addition, heat shock protein 70 (HSP70), metallothionein 1 (MT1), and glutamine synthetase 2 (GS2) were also markedly up-regulated by H2O2 and Ca under drought stress. However, the transcript level of lipoxygenase 3 (LOX3) was significantly down-regulated by H2O2 and Ca under well-watered and drought conditions. These results imply that H2O2 and Ca commonly or differentially regulate genes expression in association with drought tolerance through activating Ca signaling pathway and regulating transcription factors and stress-protective genes expression, leading to the alleviation of lipid peroxidation, maintenance of correct protein folding and translocation, and enhancement of nitrogen metabolism under a prolonged period of drought stress in creeping bentgrass.

Spermine (Spm) regulates water balance involved in water channel proteins, aquaporins (AQPs), in plants. An increase in endogenous Spm content via exogenous Spm application significantly improved cell membrane stability, photosynthesis, osmotic adjustment (OA) and water use efficiency (WUE) contributing to enhanced tolerance to water stress in white clover. Spm upregulated TrTIP2-1, TrTIP2-2 and TrPIP2-7 expressions and also increased the abundance of TIP2 and PIP2-7 proteins in white clover under water stress. Spm quickly activated intracellular Ca2+ signaling and Spm-induced TrTIP2-2 and TrPIP2-7 expressions could be blocked by Ca2+ channel blockers and the inhibitor of Ca2+-dependent protein kinase in leaves of white clover. TrSAMS in relation to Spm biosynthesis was first cloned from white clover and the TrSAMS was located in the nucleus. Transgenic Arabidopsis overexpressing the TrSAMS had significantly higher endogenous Spm content and improved cell membrane stability, photosynthesis, OA, WUE and transcript levels of AtSIP1-1, AtSIP1-2, AtTIP2-1, AtTIP2-2, AtPIP1-2, AtPIP2-1 and AtNIP2-1 than wild type in response to water stress. Current findings indicate that Spm regulates water balance via an enhancement in OA, WUE and water transport related to Ca2+-dependent AQP expression in plants under water stress.