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Discrete oligo- and polyesters are highly attractive for a wide range of investigations because of their great fidelity on structure–property relationships. Even though numerous synthetic approache...

The histone methyltransferase EZH2 silences gene expression via H3 lysine 27 trimethylation and has been recognized as an important antitumour therapeutic target. However, the clinical application of existing EZH2 inhibitors is not satisfactory for the treatment of solid tumours. To discover novel strategies against head and neck squamous cell carcinoma (HNSCC), we performed genomics, metabolomics and RNA omics studies in HNSCC cells treated with EZH2 inhibitors. It was found that EZH2 inhibitors strongly induced the expression of genes in cholesterol synthesis. Through extensive drug screening we found that inhibition of squalene epoxidase (a key enzyme of endogenous cholesterol synthesis) synergistically increased the squalene content and enhanced the sensitivity of HNSCC cells to EZH2 inhibitors. Our findings provide an experimental and theoretical basis for the development of new combinations of EZH2 inhibitors to treat HNSCC.

Liquid–liquid equilibrium (LLE) data of the ternary system 2-methyl-2-butanol + water + o-xylene were determined at 303.2, 313.2, and 323.2 K under 101.3 kPa. The extraction capacity of o-xylene is...

Previously, it was found that the hepatitis C virus NS5A interacted with ACBD3 in a genotype-dependent manner. However, the region in NS5A responsible for association with ACBD3 is not clear. Domain I of NS5A was identified as critical for ACBD3 binding. By comparing the differences of amino acids in domain I from different genotypes of NS5A, it was found that key amino acids potentially corresponded to the affinity of the NS5A-ACBD3 interaction. The findings not only revealed that domain I of NS5A associates with ACBD3 but they also shed mechanistic light on how NS5A is associated with ACBD3 in a genotype-dependent manner.

Carrier recombination and charge loss at the interfaces of perovskite layers have a significant influence on high-performance planar perovskite solar cells (PSCs). We employed two-dimensional graphitic carbon nitride (g-C3N4), which is a heat-resistant n-type semiconductor, to modify the electron-transport layer/perovskite and perovskite/hole-transport layer interfaces, respectively. g-C3N4 could passivate the surface trap states of the methylammonium lead iodide light absorber through the formation of a Lewis adduct between N and the under-coordinated Pb, and it could also remarkably reduce the grain boundaries between perovskite crystal particles. A maximum power conversion efficiency (PCE) of 19.67% (Voc = 1.14 V, Jsc = 21.45 mA cm−2, FF = 0.807) could be obtained from planar PSCs with long-term stability using dual-positioned g-C3N4. Therefore, we consider that ultrathin semiconductor films with a Lewis base nature are suitable as dual-functional transport materials for devices. This work provides new guidance for dual-interfacial modification to improve the PCE and stability of devices.

Protonation/deprotonation is the well-recognized mass spectrometric mechanism in matrix-assisted laser desorption ionization of organic molecules but not for metal ions with different oxidation states. We describe herein a soft evaporation and ionization technique for metal ions based on iodination/de-iodination in metal-iodide cluster ionization (MICI). It is not only able to determine identities and oxidation states of metal ions but also reveal spatial distributions and isotope ratios in response to physiological or environmental changes. A long chain alcohol 1-tetradecanol with no functional groups that can absorb laser irradiation was used to cover and prevent samples from direct laser ablation. Upon the irradiation of the third harmonic Nd3+:YAG (355 nm, 3 ns), iohexol containing three covalently bonded iodine atoms instantly generates negative iodide ions that can quantitatively form clusters with at least 14 essential metal ions present in plants. The detection limits vary with different metal ions down to low fmol. MICI eliminates the atomization process that obscures metal charges in inductively coupled plasma mass spectrometry. Because only metal ions can be iodinated with iohexol, interferences from the abundant organic molecules of plants that are confronted by secondary ion mass spectrometry (SIMS) are also greatly decreased.

Research on underground coal mines has primarily focused on the stability of roadways. Mining activities lead to significant damage to the surrounding rocks and also degrade the support to the roadways. Considering the 21309 roadway of the Huojitu coal mine as a case study, this work comprehensively analyzed the characteristics of the surrounding rock using three methods: theoretical calculations, FLAC3D numerical modeling, and field observations. The results indicate that, under the influence of secondary mining, the failure range and stress concentration degree of the surrounding rock are considerably higher than those under the influence of primary mining. In this case, the maximum damage range in the surrounding rock can reach 1.8 m, the maximum principal stress can reach 19.82 MPa, and the ratio of the maximum principal stress to the minimum principal stress can reach 1.95. According to the results, the previous support design for roadways was optimized and applied in the field. Field monitoring revealed that the roadway deformation was effectively controlled, and the optimized support design was safe and reliable. This study is expected to serve as a reference for support designs or optimization under similar geological conditions.

This work aimed to perform the insight into the performance at early age of cement paste/mortar with calcium silicate hydrate seeds–polycarboxylate (C-S-Hs-PCE) and aluminum sulphate. The p...

Liquid–liquid equilibrium (LLE) data for the ternary system sec-butyl alcohol + sec-butyl acetate + ethylene glycol were determined at 298.2, 308.2, and 318.2 K under 101.3 kPa. The extraction capa...

Triethanolamine (C6H15NO3, TEA) is one of the known organic amine accelerators for the cement-based materials. Triethanolamine hydrochloride (C6H15NO3·HCl, TEA·HCl), part of whose molecular structure is the same as TEA, can also be regarded as chloride. Thus the water requirement for the normal consistency, setting time, strength, hydration heat liberation, calcium hydroxide (CH) and ettringite (AFt) contents in the hardened paste with TEA·HCl were analyzed and the effect of TEA·HCl on the performance of cement paste was studied to assess the feasibility of TEA·HCl used as an identical accelerator. The results indicate that moderate TEA·HCl decreases the water requirement for the normal consistency and this decline is related to the formation of the absorbed film on the cement particle. Zeta electric potential result also proves the appearance of the absorbed film. It also shortens the setting times and alters strengths. But the alterations of setting times and strengths depend on the TEA·HCl content. Heat liberation result implies that it delays the end time of the induction period and also postpones tricalcium silicate (3CaO·SiO2, C3S) hydration at early age, however moderate TEA·HCl increases the rate of C3S hydration in accelerated phase. Excessive TEA·HCl accelerates the AFt conversion to monosulfoaluminate (AFm) after several hours. The conversion product is the AFm with 14 H2O. TEA·HCl changes the total heat liberation, and these pastes with more TEA·HCl liberate more heat before about 12 h, but this case is reverse after about 12 h. X-ray powder diffraction (XRD) and differential thermal analysis (DTA) results conformably confirm that excessive TEA·HCl delays C3S hydration and decreases CH content in the hardened paste, but it increases the AFt content in the hardened paste. Hardened pastes with TEA·HCl provide the higher content of AFt than the control even at 28d. Heat liberation, CH and AFt contents are closely responsible for the results of the setting times and strengths. These results will provide a reference for the TEA·HCl application as an accelerator in the practice.

A protonation/deprotonation mechanism has been established for the interpretation of ions in MALDI. We show herein that negative ions can be generated in different ways. Molecules with different electron affinities have been spotted on surfaces of TiO2, ZnO, and a stainless steel plate for the investigation of electron capture dissociation in comparison with photo- or thermal-induced deprotonation upon irradiation of the third harmonic of Nd3+:YAG (355 nm) laser pulses. Detection of C60•- and Fe (II) (porph•-) radical anions unambiguously demonstrates the electron-transfer process and the exothermic capture of electrons. Radical anions of fatty acids were difficult to observe because of electron-directed ultrafast homolytic cleavage of O-H bonds unless there is a conjugated system as that in C60 and porphyrin for the delocalization and stabilization of acquired changes. The surface basicity of substrate materials was found to determine the competition of the electron-capture dissociation with deprotonation processes. Multiple electron transfers to pyrrole, -COOH, and Fe2+ of the heme were observed on TiO2 and the stainless steel plate but not on ZnO. When the heme was deprotonated by proton sponge 1,8-bis(dimethylamino)naphthalene, the occurrence of electron transfer on TiO2 was also not observed. It is proposed that negative charges of deprotonated ions prevent electron transfer due to the repulsive force. When both deprotonation and electron transfer are inhibited, adsorbed fatty acids on TiO2 undergo dehydration reactions to form titanium esters. In contrast, ZnO generates gaseous micelles composed of positive metal ions and negative fatty acid ions through either deprotonation or electron-capture dissociation.

Electron transfer crucial to bioenergetics is ubiquitously present in biological systems but most of them escape from direct observations. By using tryptophan and its derivatives with 1-CH3, 2-CH3, 5-CH3 and 5-OH substitutions as model molecules, we have unambiguously demonstrated successive two-electron transfer to tryptophan as well as electronic and vibrational excited molecular dissociation with mass spectrometry. The ultra-short time delay between two electrons down to sub-attosecond over a distance less than 10 Å was found to cause the strong coupling of electronic and vibrational excitations that was validated by the observation of radical-radical coupling. Intramolecular H migrations along with two-electron transfer was demonstrated with H/D exchange and 13C stable isotope labeling. This proposed technique allows us to observe the ultrafast electron transfer from tryptophan to the heme group in myoglobin proteins. It bridges electron transfer to energy transfer that has been revealed in FRET alone. FeII (porph•‐) and FeI (porph•‐) resulting from one- and two-electron transfer, respectively, have been unambiguously identified

A novel cascade photoelectrochemical (PEC) signal amplification sensing strategy was designed and applied in target DNA detection by introducing quantum dots (QD) as the accompanying tag. The CdTe QD was labeled onto a designed sequence of single stranded DNA forming S-QD, which could be further hybridized with another magnetic bead labeled conjugate, leading to a metastable structure. In the presence of the detecting target, the S-QD could be released from the metastable structure via toehold strand displacement. With the help of the designed strand (H), the target could be released and triggered the cascade amplification. In the magnetic field, the S-QD could be easily separated from the reaction mixture and coated on the F-doped tin oxide (FTO) electrode leading to the “signal on” PEC response. The designed cascade amplification photoelectrochemical strategy exhibited a detection limit of 0.76 pM target DNA, and a linear range from 1 pM to 50 nM, indicating promising application in DNA or related analysis. Moreover, compared with other tags such as fluorescent dye, the quantum material leads to less unspecific adsorption and better sensing reproducibility, due to the appropriate nano size and high quantum efficiency.

Development of analytical techniques that can monitor the adsorption, transfer and in-situ distribution of environmental pollutants in agricultural products is essential to ensure the implementation of stringent food safety standards for consumer protection. A mass spectrometric imaging approach is described herein to investigate the dynamic changes and spatial distributions of 4, 4’-DDT (dichlorodiphenyltrichloroethane) in soybean seeds and sprouts during the growth. Soy beans seeds incubated in DDT containing water were sliced in every 20 μm and directly blotted on the surface of a compressed thin film of (Bi2O3)0.07(CoO)0.03(ZnO)0.9 nanoparticles. Endogenous molecules and exogenous DDT compounds in soy bean seeds were ionized and dissociated by photoelectrons that are generated on surfaces of semiconductor nanoparticles upon the irradiation of the 3rd harmonic (355 nm) of Nd3+:YAG laser. Structural identification is achieved by the interpretation of fragment ions resulting from electron-initiated specific bond cleavages or hole oxidization. Mass spectrometric images reveal increased quantities of DDT residues in soy bean seeds and sprouts during the growth. It provides an in situ way without extensive sample preparation to monitor the transfer and distribution of exogenous pollutants as well as the possible impacts on plant growth.

Rho GTPase-activating protein (Rho-GAP) and Rho GDP dissociation inhibitor (Rho- GDI) are two main negative regulators of Rho GTPase. Our previous work has found that Rho-GDI and Rho GTPase are involved in the response of human periodontal ligament (PDL) cells to mechanical stress. However, whether Rho-GAP also has a role in this process remains unknown. Here, we attempted to find the Rho-GAP gene that may be involved in pathological stretch-induced apoptosis of PDL cells. Human PDL fibroblasts were exposed to 20% cyclic strain for 6 hours or 24 hours, after which the expression levels of ARHGAP10, ARHGAP17, ARHGAP21, ARHGAP24 and ARHGAP28 were determined. Results showed that ARHGAP17 expression decreased the most obviously after treatment of stretch. In addition, ARHGAP17 overexpression abolished 20% cyclic strain-induced apoptosis. Therefore, ARHGAP17 has an important role in pathological stretch-induced apoptosis of human PDL fibroblasts. Moreover, we found that ARHGAP17 overexpression also alleviated cyclic strain-induced activation of Rac1/Cdc42, a major downstream target of ARHGAP17. Furthermore, two Rac1 inhibitors, NSC23766 and EHT 1864, both attenuated ARHGAP17 knockdown-mediated apoptosis in human PDL fibroblasts. Collectively, our data demonstrate that ARHGAP17 inhibits pathological cyclic strain-induced apoptosis in human PDL fibroblasts through inactivating Rac1/Cdc42. This study highlights the importance of Rho signalling in the response of human PDL fibroblasts to mechanical stress.

Artificial muscles triggered by light are of great importance, especially for the development of non-contact and remotely controlled materials. Common materials for synthesis of photoinduced artificial muscles typically rely on polymer-based photomechanical materials. Herein, we are able to prepare artificial muscles using a mixed-matrix membrane strategy to incorporate photomechanical molecular crystals with connective polymers (e.g. PVDF). The formed hybrid materials inherit not only the advantages of the photomechanical crystals, including faster light response, higher Young's modulus and ordered structure, but also the elastomer properties from polymers. This new type of artificial muscles demonstrates various muscle movements, including lifting objects, grasping objects, crawling and swimming, triggered by light irradiation. These results open a new direction to prepare light-driven artificial muscles based on molecular crystals.

The aim of this work was to investigate the migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln, and better understand the emission of the sulfur related pollutants in this process. In consideration of the temperature conditions in the practical operation, municipal sewage sludge was pre-dried at 105 °C, and then dried at 210, 260 and 310 °C, co-combusted with cement raw mill at 800, 900 and 1000 °C, and 1350, 1400 and 1450 °C respectively in the laboratory. X-ray photoelectron spectroscopy (XPS) was used to determine the S2p spectral lines of the municipal sewage sludge treated in the different process. Besides, The Thermal Analysis-Thermogravimetry (DTA-TG), Back Scattered Electron (BSE) and Energy Dispersive Spectrometer (EDS) were also employed to explore the mechanism of sulfur subsistence at 1450 °C. The results indicate that sulfide, thiophene, sulfone and sulfate are mainly sulfur compound in the municipal sewage sludge dried at 105 °C. Sulfoxide, a new sulfur compound, appears after it is further dried at 210 °C. The relative contents of sulfide and thiophene are continuously declined as the drying temperature increases due to their evaporation, decomposition and transformation in this process. The transformation of sulfide and thiophene makes the relative contents of sulfoxide and sulfate accordingly increased. However, the relative content of sulfone experiences an elevating-lowering process while the dry temperature elevated from 210 to 310 °C. This case is related to its evaporation and decomposition, as well as its production for the transformation of sulfide and thiophene. In the co-combustion process, sulfide, thiophene and sulfone are entirely vanished for their evaporation, decomposition and transformation. Sulfone is still contained at 800 °C, but when the temperature unceasingly rises, it is completely decomposed or evaporated and sulfate is the only sulfur compound. The microstructures left by the gas release are also observed in the mixtures sintered at 1450 °C, however sulfate still exists even at 1450 °C. The BSE and EDS results show that the melt phase is the important contribution to the appearance of sulfate at the high temperature. These results will sever as a theoretically reference for the pollution control of the sulfur related pollutants in the disposal process of the municipal sewage sludge in cement kiln.

This work aims to develop another approach to the management of magnesium slag (MS) via the production of Portland cement clinker. Thus, 0, 10, 20, 30, 40 and 50% limestone was replaced by MS and the clinker was sintered. The burnability of the clinker, immobilization of heavy metals in the clinker, crystalline phases, micrograph of the clinker, the setting time of paste, compressive strength and leachability of heavy metals in the hardened paste were investigated to assess the feasibility of disposing the MS via production of Portland cement clinker. The results show that MS is favourable for improving the burnability of the clinker. The heavy metals from MS are stabilized/immobilized in clinker. MgO and CaF2 in MS increase the quantity of the liquid phase. All major phases of Portland cement appear in all clinkers with MS. However, the content of C3S in the clinker is related to the MS content. Less than 30% MS shortens the setting times of cement and increases the compressive strength for the increment of the C3S content in these clinkers. Excessive MgO and CaF2 lead to the decrease of C3S and appearance of unconventional cement phases of α-C2S and γ-C2S in MS4 and MS5. Thus, the setting times of MS4 and MS5 are prolonged, and their compressive strengths are also reduced. Heavy metals in clinkers are immobilized or stabilized in hydrated matrices. MS disposal via the production of Portland cement as a raw material alternative is also environmentally safe.

Enhanced antiinfection activities, improved hemocompatibility and osteo-compatibility, and reinforced osseointegration are among the most important considerations in designing multifunctional orthopedic biomaterials. Hereby, anti-infective and osteogenic multifunctional 3D printed porous Ti6Al4V implant with excellent hemocompatibility was successfully designed and fabricated. In brief, osteogenic micro-arc oxidation (MAO) coatings with micro/nanoscale porous topography were generated in situ on 3D printed Ti6Al4V scaffolds, on which heparin and vancomycin were easily immobilized. The surface microstructure, morphology, and chemical compositions were characterized employing scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). High loading capacity and sustained vancomycin release profiles were revealed using high performance liquid chromatography (HPLC). Favorable antibacterial and antibiofilm performances against pathogenic Staphylococcus aureus ( S. aureus ) were validated in vitro through microbial viability assays, Live/Dead bacterial staining, and crystal violet staining. Human mesenchymal stem cells (hMSCs) were seeded on the scaffolds and their proliferation and viability were assessed using Cell Counting Kit and Live/Dead cell viability kit. Further, osteoblastic differentiation abilities were evaluated using alkaline phosphatase (ALP) activity as a hall marker. Additionally, the improved hemocompatibility of the heparinized scaffolds was confirmed by activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT). Overall, our results show that the surface-modified 3D printed porous Ti6Al4V possesses balanced antibacterial and osteogenic functions while exhibiting extra anticlotting effects, boding well for future application in customized functional reconstruction of intricate bone defects.

The passivation strategy is considered to be one of the most effective methods to suppress the non-radiative recombination of perovskite solar cells (PSCs), resulting in excellent photovoltaic performance. Herein, it reported a valid strategy to enhance the photoconversion efficiency (PCE) of PSCs by modifying graphitic carbon nitride (g-C3N4) nanosheets into an electron transport layer interface. It is able to optimize surface morphology and crystal quality of perovskite film, which makes synergistic efforts to improve the PCE from 9.55% to 11.37% with these devices.

Mesoporous carbon (MC) and nitrogen-doped mesoporous carbon (NMC) were prepared through a dual-template approach with tetraethyl orthosilicate and Pluronic F127 as a dual-template, and phenol-formaldehyde and melamine-phenol-formaldehyde resins as carbon and carbon + nitrogen sources, respectively. Using them as the supports, the Pt/MC and Pt/NMC catalysts were prepared by incipient wetness impregnation method and used for the decarboxylation of saturated and unsaturated fatty acids to alkanes. Activated carbon supported Pt catalyst (Pt/AC) was also prepared for comparison. Among the three catalysts, Pt/NMC exhibited the highest catalytic performance, achieving yields of the corresponding alkanes of more than 97.0% from lauric, myristic, palmitic and stearic saturated acids and 44.0%–66.1% from oleic and linoleic unsaturated fatty acids. The turnover frequencies of Pt/NMC were estimated as 335–522 h−1 in the decarboxylation of saturated acids, which were almost 2-fold higher than Pt/MC and 3-fold higher than Pt/AC. The excellent performance of the Pt/NMC catalyst might be attributed to the introduction of N species to the MC support, which not only improved the anchoring and the dispersion of Pt nanoparticles on the catalyst surface, but also provided alkaline sites to adsorb carboxyl group in fatty acids.

Biomass-based porous carbons as electrode materials in asymmetric Li-ion capacitors (LICs) have shown broad prospect application. In this work, one kind of copper hyperaccumulator-elsholtzia splendens was selected as biomass source to synthesize micro-/nanoporous carbons to be used as both anode and cathodefor LICs due to the need of waste disposal. On the basis of separate charge storage mechanisms of anode and cathode in this system, corresponding strategies were adopted to rationally optimize the microstructure of micro-/nanoporous carbons to promote their electrochemical performance. Electrochemical tests showed that hierarchical porous carbon microsphere (PECS) anode exhibited an excellent rate capability (215.6 mA h g−1 at 2 A g-1) and a long lifespan (87.1% capacity retention over 1000 cycles). Carbon cathode with an ultrahigh specific surface area of 2819 m2 g-1 revealed a high specific capacity of 90.9 mA h g−1 at 5 A g-1. Benefiting from the high rate capability of anode and the high specific capacity of cathode, the as-assembled LIC delivered a high energy density of 129.4 W h kg−1 and 51.9 W h kg−1 at a power density of 205.5 W kg−1 and 10.3 kW kg−1.

To improve the photoelectric performance of dye sensitized solar cells (DSSCs), graphene oxide (GO), upconversion luminescent material NaYbF4:Ho3+ (UC) and porous hollow titanium dioxide microspheres (PHTS) were synthesized to couple with the commercial P25 for improving the light-harvesting of DSSCs. In the composited nanostructure, the GO reduces the internal charge recombination, while the UC doping broadens the absorption spectral range, both of which were applied to the novel PHTS for improving the dye adsorption capacity and light utilization. The P25, P25/GO, P25/UC/GO, P25/UC/GO + PHTS photoanodes were fabricated and the morphology and photoelectric performance were analyzed respectively. Among them, DSSC using P25/UC/GO + PHTS photoanode showed the best performance with the power conversion efficiency (PCE) reaching as high as 9.41%.

Current management for red mud is insufficient and a new method is needed. A series of experiments have been carried out to develop a new approach for effective management of red mud. Mortars without or with 3%, 6% and 9% red mud were prepared and their fresh and hardened properties were measured to access the possibility of recycling the red mud in the production of red cement-based mortar. The mechanisms corresponding to their mechanical performance variations were explored by X-ray powder diffraction and scanning electron microscopy. The results show that the fresh mortars with red mud present an increase of viscosity as compared with the control. However, little difference is found when the content of red mud is altered. It also can be seen that red mud increases flow time and reduces the slump flow of the mortar. Meanwhile, it is found that mortar with red mud is provided with higher air content. Red mud is eligible to adjust the decorative mortar colour. Compressive strength of mortar is improved when less than 6% red mud is added. However, overall it has a slightly negative effect on tensile bond strength. It decreases the Ca(OH)2 content and densifies the microstructure of hardened paste. The heavy metal concentrations in leachates of mortars with red mud are much lower than the values required in the standard, and it will not do harm to people’s health and the environment. These results are important to recycle and effectively manage red mud via the production of red cement-based mortar.

The overall objective of this research was the preparation of optical nanocomposite photoanodes through a simple method. The synthesized nanocomposite photoanodes were then used to improve the power conversion efficiency of dye-sensitized solar cells (DSSCs). Titanium dioxide (TiO2) nanofibers (NF) were prepared via electrospinning and calcination. Then, thin films were prepared with commercial TiO2 (NP) as a binder. Different concentrations of zinc oxide (ZnO) nanoparticles were used to impregnate TiO2 NP/NF. When the prepared nanostructures were used as photoanodes, the DSSCs based on NP/NF–ZnO film with an optimum concentration of ZnO (3.5 M) exhibited the highest short circuit current density (Jsc) of 12.83 mA cm−2 and open circuit voltage (Voc) of 0.764 V. The NP/NF–ZnO photoanode also exhibited a maximum power conversion efficiency (PCE) of 6.54%, which was higher by 26.5% than that of NP/NF (5.17%) with the same electrolyte.

Distinguishing b- and y-ions is essential to compute amino acid sequences from either N- or C-terminus in mass spectrometry. We described herein a solvent free and real time on-plate derivatization approach that can tag N-terminus of peptides at microliter level with p-chlorobenzaldehyde or 2-hydroxy-5-methylisophthalaldehyde for matrix assisted laser desorption ionization mass spectrometry (MALDI MS). Less than 1 μL of sample solutions can be directly mixed with equal volumes of p-chlorobenzaldehyde or 2-hydroxy-5-methylisophthalaldehyde and α-cyano-4-hydroxycinnamic acid (CHCA), a matrix compound to co-crystalize with analytes for efficient absorption of laser energy and peptide ionization. When the mixture spotted on the sample plate is irradiated with the 3rd harmonic (355 nm) of Nd3+:YAG laser pulses (3 ns width), N-terminal amine groups of peptides instantly react with carbonyl groups of chlorobenzaldehyde or 2-hydroxy-5-methylisophthalaldehyde. Resultant peptides carrying with on-plate formed azomethine group (-C N-) are simultaneously protonated and isolated as precursor ions for subsequent collision-activated dissociation. The mass shift with unique Cl isotopic signature unambiguously distinguishes b ions from y ions and other ions. This method does not need extensive sample preparation and is useful for those samples with limited quantities down to sub-picomole level in sub-microliter volumes. The efficiency was demonstrated with synthetic peptides and tryptic peptides of model proteins. It was found that 2-hydroxy-5-methylisophthalaldehyde provides improved yield for peptides containing lysine residues. Unknown proteins of human saliva and bovine milk as well as phosphopeptides have been identified.

Naphthalene sulfonate-formaldehyde condensatation (NSF) is the main component of the naphthalene based water reducers for cement based materials, as well as an organic substance with potential toxicity. However it is still uncertain whether it can leak from the cement based materials. In this work, the leakage ratio and adsorption behavior of NSF from various cement based materials such as the different water/cement (w/c) ratio, NSF content, types of cementitious materials as well as at different hydration time were evaluated. The product components of the cement based materials cured for different times were also quantified to explore the mechanisms which are responsible for the leakage and adsorption behaviors. The results indicate that more NSF, lower w/c ratio and less mineral admixture decrease the NSF leakage ratio. The leakage ratio of NSF from cement paste mixed 0.3% NSF is up to 50.8% at 0.5 h, and it decreases to 31.0% at 28 d. The leakage ratio of NSF from cement paste decreases as the hydration time prolongs. The lower leakage ratio corresponds to the higher adsorption capacity. Less adsorption capacity and thinner adsorption film imply that lower temperature and mineral admixture decrease the NSF adsorption behavior. When 0.3% NSF is added into the cement paste, the adsorption amount and NSF layer thickness are 5.53 mg/g and 0.98 nm, 5.87 mg/g and 4.7 nm at 0.5 h and 28 d respectively. The result demonstrates that the adsorption behavior of NSF in cement significantly increases at the initial several hours and gradually stabilizes after the first day. The X-ray powder diffractometer (XRD) results show that the contents of tricalcium silicate (C3S) and dicalcium silicate (C2S) continuously decline and the amorphous phases and ettringite (AFt) increase rapidly in the early stage. NSF adsorption and leakage behaviors are closely related to the hydration process of cement. These results indicate that NSF can definitely leak from the cement based materials and thus the NSF potential environmental pollution cannot be ignored. At least, it should be restricted or cautious to produce the water tower and pipe concrete structure with it. These results will sever as a theoretically reference for the pollution control as well as better application of NSF in cement-based materials.

SnO2 has attracted extensive attention in planar perovskite solar cells (PSCs) owing to its outstanding photoelectric properties and low temperature preparation. However, pinholes are easy to appear in the annealing process of SnO2 films, which limits its application in planar PSCs. Here lists a simple and low-cost method: Urea-complexed tin oxide in deionized water can effectively control the concentration of SnO2. This process is conducive to forming a compact surface morphology. Meanwhile, the work explored the effect of the properties of PSCs with different thicknesses of SnO2 layers. The system analysis showed that PSCs based on 60 nm SnO2 layer and the methamphetamine lead iodide (MAPbI3) light absorber yielded the highest power conversion efficiency (PCE) over 18%, a fill factor (FF) of 0.793, and good stability. Therefore, we believe our study provides an effective way for preparing electron transport layers.

This paper aimed at investigating the action of the combined presence of calcium silicate hydrate seeds - polycarboxylate (C-S-Hs-PCE) and triethanolamine (TEA) on the performances of cement paste/mortar. Simultaneously, the mechanisms behind this action were explored. The results demonstrate that the composite addition of C-S-Hs-PCE and TEA further promotes the setting behaviour of cement pastes, but this promotion depends mainly on the TEA content. The composite use of 0.02% TEA and 0.5–2% C-S-Hs-PCE increases the mortar compressive strengths at 1, 3, 7 and even 28 days. This increase is related to the promotion of tricalcium silicate (C3S) hydration at 1 and 3 days, the increment of the calcium hydroxide (CH) content over 1–28 days, and the decrement of the number of gel pores and the volumes of the pores with sizes of less than 100 nm in the pastes with 0.02% TEA and 0.5%–2% C-S-Hs-PCE. However, the composite addition of 0.5%–1% TEA and 0.5%–2C-S-Hs-PCE reduces the compressive strengths at 1 and 28 days: 0.5%–1% TEA and 0.5%–2% C-S-Hs-PCE enhance the monosulfate (AFm) content at 1 day, promote the reaction from ettringite (AFt) to AFm, decrease the CH content, retard the C3S hydration at 1 day and 3 days and increase the gel pore quantity and the volume of the pores that are distributed from several nm to 100 nm. As a result, the mortars with 0.5%–1% TEA and 0.5%–2% C-S-Hs-PCE exhibit lower compressive strengths at 1 day and 28 days. These findings provide theoretical guidance for the composite use of TEA and C-S-Hs-PCE in cement-based materials.

It is still uncertain whether β-hemihydrate and dihydrate gypsum influence the properties, especially the phase conversion, of white calcium aluminate cement (CAC). Therefore, in this study, we prepared CAC pastes/mortars containing β-hemihydrate and dihydrate and comparatively assessed their setting times and compressive strengths. Simultaneously, the influence of β-hemihydrate and dihydrate on their chemical shrinkage, hydration-heat, pore size distributions, crystalline, and thermogravimetric characteristics was investigated. It is interesting that 0.5% β-hemihydrate and dihydrate significantly postponed the setting, whereas more than 0.5% β-hemihydrate and dihydrate slightly prolonged the initial setting and significantly shortened the final setting. Both β-hemihydrate and dihydrate decreased the compressive strength of CAC pastes hardened for 1 and 3 days to different extents; however, CAC pastes with a β-hemihydrate or dihydrate content less than 1% exhibited a high compressive strength at 28 days. Beyond this dosage, the compressive strength of the specimens was found to reduce. In addition, CAC pastes containing more than 0.5% β-hemihydrate or dihydrate exhibited high chemical shrinkage over 3–12 h. Furthermore, β-hemihydrate and dihydrate enhanced the gel micro and meso pores. They accelerated or decreased CAC hydration in the fast reaction and first deceleration periods, prolonged or shortened the induction period, enhanced or reduced the hydration heat before or after 12 h. These cases are closely associated to their contents. Their inclusion restricted CAH10 formation while promoting the generation of C2AH8, AFm, and AH3 and conversion of CAH10 to C3AH6 after 3 days. Besides, there are some significant differences in their influence on the properties and phase conversion of CAC pastes. For these differences, CAC pastes/mortars with β-hemihydrate and dihydrate presented different setting times and compressive strengths.

Current management for red brick waste is insufficient, and a new method is needed. We sought to develop a new approach for effective management. Red cement-based decorative plasters were prepared with red brick waste powder (RBWP), white Portland cement, quartz sand, redispersible emulsion powder, hydroxypropyl-methyl cellulose ethers and silicone hydrophobic agent. The colors, water absorptions and strengths of different plasters were investigated, and the mechanisms responsible for their performance variations were explored by high-resolution transmission electron microscopy, X-ray powder diffractometry and scanning electron microscopy. The relative economic and environmental benefits were also analyzed. The feasibility of recycling RBWP in the production of cement-based red decorative plaster for walls was evaluated. The resulting plaster provided appropriate color adjustment, and the water resistance of the plaster was not greatly affected. The compressive and flexural strengths of plaster were improved. However, the improvement decreased as the sand replacement ratio increased. The tensile bond strength of the plaster is related to the RBWP content. More RBWP negatively affects the tensile bond strength of the plaster. Calcium hydroxide in the hardened paste varies with RBWP content. This variation correlates with the appearance and level of pozzolanic reaction in the plaster with RBWP. Plaster with RBWP has a denser microstructure than the control. In addition to the pozzolanic reaction, this denser microstructure also contributes to performance improvements such as compressive and flexural strengths. To improve the economic and environmental efficiencies, it is also feasible to recycle RBWP in the production of cement-based red decorative plaster for walls. These results demonstrate the effective use of red brick waste. They also provide a reference strategy for the management of red brick waste in other developing countries that are carrying out or will carry out urbanization activities.

KADIOGLU, Asim/0000-0002-4781-6264; PEHLIVAN, NECLA/0000-0002-2045-8380 WOS: 000376654200019 PubMed: 26985021 The Arabidopsis gene AtNHX1 encodes a vacuolar membranebound sodium/proton (Na+/H+) antiporter that transports Na+ into the vacuole and exports H+ into the cytoplasm. the Arabidopsis gene SOS1 encodes a plasma membranebound Na+/H+ antiporter that exports Na + to the extracellular space and imports H + into the plant cell. Plants rely on these enzymes either to keep Na + out of the cell or to sequester Na + into vacuoles to avoid the toxic level of Na + in the cytoplasm. Overexpression of AtNHX1 or SOS1 could improve salt tolerance in transgenic plants, but the improved salt tolerance is limited. NaCl at concentration > 200mM would kill AtNHX1-overexpressing or SOS1-overexpressing plants. Here it is shown that co-overexpressing AtNHX1 and SOS1 could further improve salt tolerance in transgenic Arabidopsis plants, making transgenic Arabidopsis able to tolerate up to 250mM NaCl treatment. Furthermore, co-overexpression of AtNHX1 and SOS1 could significantly reduce yield loss caused by the combined stresses of heat and salt, confirming the hypothesis that stacked overexpression of two genes could substantially improve tolerance against multiple stresses. This research serves as a proof of concept for improving salt tolerance in other plants including crops. Howard Hughes Medical InstituteHoward Hughes Medical Institute This research was supported by a Howard Hughes Medical Institute grant through the Undergraduate Science Education Program to Texas Tech University.

We examined the response of soil CO2emissions to warming and environmental control mechanisms in an alpine swamp meadow ecosystem on the Tibetan Plateau. Experimental warming treatments were performed in an alpine swamp meadow ecosystem using two open-top chambers (OTCs) 40 cm (OA) and 80 cm (OB) tall. The results indicate that temperatures were increased by 2.79°C in OA and 4.96°C in OB, that ecosystem CO2efflux showed remarkable seasonal variations in the control (CK) and the two warming treatments, and that all three systems yielded peak values in August of 123.6, 142.3, and 166.2 g C m−2 month−1. Annual CO2efflux also showed a gradual upward trend with increased warming: OB (684.1 g C m−2 year−1) > OA (580.7 g C m−2 year−1) > CK (473.3 g C m−2 year−1). Path analysis revealed that the 5 cm depth soil temperature was the most important environmental factor affecting soil CO2emissions in the three systems.

Friedel’s salt usually forms in cement paste with CaCl2, however, it is still uncertain whether calcium silicate hydrate seed - polycarboxylate (C-S-Hs-PCE) promotes the formation of Friedel's salt, especially improves the performances of cement paste/mortar with CaCl2. Therefore, in this study, X-ray diffraction (XRD) and differential thermal analysis (DTA) were used to quantify the Friedel’s salt content in pastes with different contents of C-S-Hs-PCE and CaCl2. Simultaneously, their setting times and compressive strengths at 1, 3 and 28 days were comparatively analyzed and the pore size distributions, hydration and chemical shrinkages of all pastes were also carried out to investigate the relative mechanism. The results reveal that C-S-Hs-PCE promotes the formation of Friedel's salt in paste with CaCl2, but this promotion is related to the contents of C-S-Hs-PCE and CaCl2. C-S-Hs-PCE hardly influences the compressive strengths at 1, 3 and 28 days of mortars with less than 2% CaCl2, however, 2% C-S-Hs-PCE significantly improves the compressive strength of mortar with 2% CaCl2. It is worth noting that it increases the specific surface area of pore in paste with CaCl2, but it decreases the volume and average diameter of pore in it. More importantly, it still enhances the heat flow in the initial fast reaction, first deceleration and induction periods of paste with CaCl2. It also advances the merged main exothermic peak and enhances the heat flow at this merged peak. It does not increase the hydration heat during 72 h, but 1–2% C-S-Hs-PCE promotes the hydration of paste with CaCl2 during 72–168 h. It leads to the further decrement in the setting times of paste with CaCl2 for the hydration promotion in the initial fast reaction, first deceleration and induction periods.

This work aimed to improve the setting behavior and strengths of cement paste/mortar with ethylene and vinyl acetate copolymer redispersible powder (EVA-DP) using C-S-H seeds and polycarboxylate superplasticizer (C-S-Hs-PCE) and meanwhile explore the reasons for these two improvements by means of the heat flow, water requirement, air content, apparent density and pore size distribution. The experimental results show that C-S-Hs-PCE used in this work notably cuts down the setting behavior and increases the strengths at 3d of mortars with EVA-DP; however, less than 2% C-S-Hs-PCE hardly increases their strengths at 28d. C-S-Hs-PCE promotes the hydration of paste with EVA-DP in several manners; it enhances heat flow in the first deceleration period, the initial several hours in the acceleration period and at the main exothermic peaks/merged peak, or advances the onset of the acceleration period, or shifts the maximum of the hydration rate to earlier time. This promotion in the hydration at different levels is the reason for the shortened setting behavior of paste with EVA-DP in the presence of C-S-Hs-PCE. Except for the promoted hydration, the increased apparent density resulted from lowered water requirement, as well as the less pores, especially the middle and large capillary pores, are the other main contributors to the increment in the strengths of mortar with EVA-DP and C-S-Hs-PCE, especially the strengths at 28d of the mortars with 6% and 10% EVA-DP and 2% C-S-Hs-PCE.

This study aims to improve the osteogenic differentiation in vitro and bone formation in vivo through polycaprolactone (PCL) scaffolds modified with the osteogenic growth peptide (OGP). Three-dimensional (3D)-printed PCL scaffolds were designed with computer-aided design (CAD) software and fabricated by 3D layer-by-layer fused deposition. After the scaffold surfaces were modified by surface amination, the OGP was successfully loaded onto the scaffolds using a electrostatic self-assembly method. The effects of these scaffolds on the biocompatibility and osteogenic differentiation of rat bone marrow-derived stem cells (BMSCs) were studied in vitro. The modification did not influence the adhesion or proliferation, but had a notable osteogenic effect in vitro. This may be attributed to the activation of the mitogen-activated protein kinase/extracellular regulated protein kinase (MAPK/ERK) signalling pathway. Based on the results obtained after implantation into a rat cranial defect model, the PCL/OGP scaffolds notably promoted bone formation and accelerated mineralisation. The innovative modification method introduced in this work, will improve the application of PCL scaffolds in tissue engineering.

Aimed to enhance the performance of the cement and powder silane water repellent based waterproof mortar, different contents of nucleation C-S-H seed were thus introduced into various mortars and pastes, their performances such as strengths, water capillary absorptions, anti-penetration capacities, drying shrinkages and chemical shrinkages were evaluated. The pore size distributions of hardened mortars, heat liberations and crystalline phases of pastes cured for different ages were also measured to explore the mechanisms which are responsible for the enhanced performances. The results indicate that the nucleation C-S-H seed significantly increases the strengths and anti-penetration capacity, reduces the water capillary absorption and drying shrinkage of the waterproof mortar. It slightly affects the chemical shrinkage, but significantly reduces the volumes of the pores, especially the gel and large capillary pores. Overall, it promotes the early hydration of the cement and powder silane paste. It accelerates the conversion of ettringite (AFt) to monosulfoaluminate (AFm) and increases calcium hydroxide (CH) content in the hardened paste cured for 3d. It cuts down the entering time of acceleration period and the contents of un-hydrated clinker phases such as tricalcium silicate (C3S) and dicalcium silicate (C2S). These results will provide a theoretical reference for the preparation of cement and powder silane based waterproof mortar with better performances.

It is still uncertain whether there are some differences between their influences of TEA and TEA·HCl on the properties of cement paste. Thus, this work aimed to evaluate the differences between their influences of TEA and TEA·HCl on the properties of cement paste. Then the cement pastes or mortars with 0%, 0.01%, 0.015%, 0.02%, 0.06%, 0.10%, 0.20%, 0.50% and 1.00% TEA and TEA·HCl respectively were prepared and their setting times and compressive strengths were investigated. Meanwhile, the chemical shrinkage, pore size distributions, hydration heat releases, thermogravimetric (TG) characteristics and microstructures of vaious pastes were studied to explore the mechanisms that are responsible for these differences. The results show that less than 0.2% TEA·HCl reduces the initial setting time more significantly, whereas 0.02%, 0.06% and 0.1% TEA·HCl are inclined to shorten the finial setting time as comparing with the same content of TEA. Less than 0.1%, 0.02% and moderate TEA·HCl more significantly enhance the compressive strengths at 3 d, 7 d and 28 d respectively in comparison to the same content of TEA. These pastes with less than 0.2% TEA·HCl have the greater chemical shrinkage at 24 and 72 h, the cement pastes with less than 0.02% TEA·HCl provide the greater rate of hydration liberation in the initial fast reaction period, these pastes with 0.2% TEA·HCl display the more significantly increaseed rate of hydration heat liberation in the acceleration period as well as the more total hydration heat liberation at 72 h, as comparing with the cement pastes with same content of TEA. Besides, TG result indicates that these hardened pastes with TEA·HCl form the more CH at 3 d, whereas these hardened pastes with less than 0.06% TEA have the more CH at 28 d. These hardened pastes with 1%, 0.2% and 0.5% TEA·HCl have the relatively less pore voume as compared with the pastes with same contents of TEA at 28 d. The result of the scanning electron microscope (SEM) image shows that in the presence of same content of TEA and TEA·HCl, TEA·HCl is more liable to alter AFt and CH morphology. These discriminative results in the chemical shrinkage, pore sizes distribution, hydration heat release, TG and SEM provide an envience for the differences between their influences of TEA and TEA·HCl on the properties of cement paste. These results will provide a reference for the selective use of TEA and TEA·HCl as an accelerator.

It is still uncertain whether nucleation calcium silicate hydrate (C-S-H) seed can really improve the reactivity of granulated blast-furnace slag (GGBS) powder and accelerate the strength development. In this work, various pastes and mortars were prepared with cement, GGBS and C-S-H seed, and their compressive and flexural strengths, chemical shrinkages, the characteristics of hydration heat liberations and CH content in the hardened pastes, and reactivity indexes and reaction degrees of the GGBS in the presence of nucleation C-S-H seed were investigated. The results show that C-S-H seed notably increases the 1, 3, 7 and 28 d strength of the 50% GGBS and 50% cement mortar. The hardened pastes with nucleation C-S-H seed provide the greater strength reactivity index than the control at 7 and 28 d, especially 0.6, 1 and 2% C-S-H seed have more significant role on this index. It also enhances the chemical shrinkage and the more significantly increased chemical shrinkage is related to the higher content of nucleation C-S-H seed as the greater chemical shrinkage implies more hydration or reaction. It shortens the induction period, cut down the acceleration stage, accelerates the conversion of AFt to AFm and enhances the total hydration heat. It reduces the calcium hydroxide (CH) content in the hardened paste, and reaction degrees of the GGBS were investigated in order to further determine the role of nucleation C-S-H seed on the reactivity of GGBS, the results show that it improves the 1, 3, 7 and 28 d reaction degrees of GGBS, 1 and 2% C-S-H seed increase the percentages of the reacted GGBS at 1, 3, 7 and 28 d about 66% and 134%, 56% and 94%, 101% and 200%, 41.7% and 46.1% respectively by the control. These results will provide a reference for the more widely application of nucleation C-S-H seed as well as the activation of GGBS reactivity.

This work aimed to assess the influence of vinyl acetate and ethylene copolymer dispersible powder (VAE-P) on the performance and interfacial transition zone (ITZ) of pervious concrete, and explore the mechanism responsible for the resulted performance. Various pervious concretes and mortars were prepared, and the porosities, water permeability coefficients and strengths of pervious concretes were assessed, the fluidities, shear viscosities, air contents and strengths of various mortars were measured. The crystalline phase, pore characteristic and VAE-P layer in the ITZ were also investigated. The results indicate that VAE-P enhances fluidity and air content, and declines shear viscosity of fresh mortar. These pervious concretes with lower or similar porosity than the control still provide similar or better water permeability. It reduces mortar strength, but it significantly improves pervious concrete strengths. ITZ results indicate that it delays cement hydration, alters pore characteristic and especially increases the volume of pores with larger size. It increases VAE-P layer thickness. The pervious concrete with 10% VAE-P displays a cross-linked network layer structure. The pervious concrete with 5% VAE-P provides the lower strengths than that with 2.5% VAE-P, but pervious concretes with more VAE-P have relatively higher strengths. These results provide a reference for the preparation of pervious concrete with VAE-P.

Taking Nanfen open-pit iron mine in Liaoning Province as the engineering background, this study analyzes the effect of water-rock circulation on the mechanical properties of rock through a combination of macro-mechanical experiments and microstructure tests in the laboratory. Uniaxial compression experiments and acoustic wave tests are used to determine the degradation law of the mechanical properties of chlorite under the periodic action of water. The experimental results show that dry-wet cycles have a continuous and gradual effect on the rock sampled: Its uniaxial compressive strength, elastic modulus, and acoustic velocity all decrease gradually with an increase in the number of cycles. After 15 wet-dry cycles, the uniaxial compressive strength and elastic modulus of the rock decreased by 34.21% and 44.63%, respectively. Electron microscope scans of the rock indicate that the particle size, characteristics, and pore distribution at the rock surface had changed significantly after water-rock interaction. Finally, a drainage system and sliding force monitoring devices have been arranged at the mine site that can effectively reduce the impact of water-rock interaction on the stability of the mine. This combination of macro-experiments and micro-analysis allowed the weakening effect of dry-wet cycles on slope rock to be studied quantitatively, providing a theoretical reference for stability evaluation in geotechnical engineering.

The cyanobacterium Nostoc sphaeroides Kutzing is expected to be effective in toxic metal adsorption as it produces abundant exopolysaccharides with functional groups. Therefore, the adsorption properties of Cu2+, Cd2+, Cr3+, Pb2+, Ni2+, and Mn2+ on fresh macrocolonies and algal powder of N. sphaeroides were compared at pH 5 and 25 °C. The adsorption capacity of fresh biomass for Pb2+ and of algal powder for Pb2+ and Cr3+ were highest in single metal solutions. Compared to the fresh biomass, the metal adsorption capacities of algal powder were similar for Ni2+, Cd2+, and Pb2+ and slightly greater for Cr3+, but they were markedly smaller for Mn2+ and Cu2+. Coexisting ions (in tap water or in multiple solutions) significantly decreased the metal adsorption capacity, except for Cr3+ in tap water. The Pb2+ and Cr3+ adsorption dynamic process fitted the pseudo-second-order model well, showing fast adsorption at the first stage in 10 and 20 min, respectively. Higher pH in acidic ranges favored the adsorption greatly. The Langmuir isotherm model was suitable for explaining the adsorption, and the maximum adsorption capacities were 116.28 and 22.37 mg g−1 for Pb2+ and Cr3+, respectively. The adsorption process was endothermic, confirmed by the significantly higher adsorption capability at higher temperature. Hydroxyl, amino, and carboxyl groups were the main functional groups based on Fourier transform infrared spectroscopy analysis, and they bind to metal ions via ion exchange. The results suggest that fresh macrocolonies of N. sphaeroides can be used as an effective biosorbent for metal ion removal, especially for Pb2+ and Cr3+.