[en] Graphical abstract: - Highlights: • Uniform Ag nanoparticle films were synthesized by a modified photocatalytic method on TiO_2 films with Ag seeds for surface-enhanced Raman scattering. • This modified photocatalytic method combine the advantages of the spurting method (high nucleation density) and the traditional photocatalytic method (suitable particle size). • The Raman enhancement of as-prepared Ag NP films was calculated by finite-difference time-domain to validate the experiment data. - Abstract: Uniform Ag nanoparticle (NP) films were synthesized by a modified photocatalytic method on TiO_2 films with Ag seeds for surface-enhanced Raman scattering, which combine the advantages of the spurting method (high nucleation density) and the traditional photocatalytic method (suitable particle size). The Ag seeds were prepared by magnetron sputtering with different time, which would adjust the distribution and transfer of electrons on the surface of TiO_2 film in the process of photocatalytic reduction. The distribution and morphology of Ag NP films can be adjusted by the sputtering time and the UV irradiation time. The Raman enhancement of as-prepared Ag NP films was calculated by finite-difference time-domain to validate the experiment data. It is found that the Ag NP films synthesized on TiO_2 films with suitable pre-deposited Ag seeds exhibit a much higher Raman enhancement activity than the optimum Ag NP film synthesized directly on the TiO_2 film without Ag seeds.

[en] Data mining was performed on 28 330 unique peptide tandem mass spectra for which sequences were assigned with high confidence. By dividing the spectra into different sets based on structural features and charge states of the corresponding peptides, chemical interactions involved in promoting specific cleavage patterns in gas-phase peptides were characterized. Pairwise fragmentation maps describing cleavages at all Xxx-Zzz residue combinations for b and y ions reveal that the difference in basicity between Arg and Lys results in different dissociation patterns for singly charged Arg- and Lys-ending tryptic peptides. While one dominant protonation form (proton localized) exists for Arg-ending peptides, a heterogeneous population of different protonated forms or more facile interconversion of protonated forms (proton partially mobile) exists for Lys-ending peptides. Cleavage C-terminal to acidic residues dominates spectra from peptides that have a localized proton and cleavage N-terminal to Pro dominates those that have a mobile or partially mobile proton. When Pro is absent from peptides that have a mobile or partially mobile proton, cleavage at each peptide bond becomes much more prominent. Whether the above patterns can be found in b ions, y ions, or both depends on the location of the proton holder(s). Enhanced cleavages C-terminal to branched aliphatic residues (Ile, Val, Leu) are observed in both b and y ions from peptides that have a mobile proton, as well as in y ions from peptides that have a partially mobile proton; enhanced cleavages N-terminal to these residues are observed in b ions from peptides that have a partially mobile proton. Statistical tools have been designed to visualize the fragmentation maps and measure the similarity between them. The pairwise cleavage patterns observed expand our knowledge of peptide gas-phase fragmentation behaviors and should be useful in algorithm development that employs improved models to predict fragment ion intensities

[en] Large numbers of gas-phase dissociation spectra of protonated peptides are obtained daily and used in protein identification studies. Yet fundamental knowledge of the factors that influence their unimolecular dissociation branching ratios is relatively poor. It is still not possible to predict dissociation branching ratios from peptide sequence. Clearly, several chemicals factors must influence dissociation patterns, includes y, f angles determined by the residues involved in an amide bond, the propensities for certain side chains to interact each other or with the backbone, the tendency for added protons to be intramolecularly solvated, and the stability of the fragment ions once formed

[en] Objective: To make the coating with polylactide coglycotide (PLGA) for the peripheral arterial stents and to study the biological properties of the coating. Methods: By using dip-covering technique the Ni-Ti alloy stent was coated with PLGA. The surface morphology, physical features, blood compatibility and degradation of the coating were observed and tested with the help of stereomicroscope and electro-scanning microscope. Results: PLGA could form a smooth coating layer on the stent surface, the coating layer kept tight cohesion with the stent even after it was repeatedly bended. Compared with naked NiTi alloy stent, there was less platelet adhesion on PLGA-coating stent. The degradation rate of the PLGA coating was rather steady, which followed the linear rule, and the complete degrading time was about 6 weeks. Conclusion: PLGA coating possess ideal surface morphology, stable bond to the stent, fine compatibility with blood and moderate degradation rate, thus, it might be of value in preventing the restenosis after stent implantation. (authors)

[en] Highlights: • The ecological health in fully enclosed reclamation areas was more disturbed than in opened reclamation areas. • Salinity desalination was a key factor in the decline of species richness of macrobenthos. • Vegetation helped to improve the effects of wetland reclamation on macrobenthos communities. • Larger soil particle diameter were positive factors for biodiversity of macrobenthos. • When large-scale reclamation of wetland was unavoidable, opened reclamation is preferable. This study compared the community structure of macrobenthos in bare tidal areas and vegetated regions under two reclamation patterns, fully enclosed and opened reclamation, in Yangtze wetland, China. Compared with fully enclosed reclamation areas, opened reclamation areas had higher water salinity, higher number of species and abundance, and less disturbed habitat health status. Compared with bare tidal areas, vegetated regions were more suitable for the survival of macrobenthos and its habitat health status was more stable. Salinity, pH and larger soil particle diameter were positively associated with macrobenthic diversity, while total nitrogen and total phosphorus were negatively associated. Overall, compared with fully enclosed reclamation and vegetated regions, opened reclamation and bare tidal areas had less negative effects upon macrobenthic community and habitat health. Opened reclamation is preferred for wetland reclamation, and planting indigenous plants and releasing species adapted to fresh water is beneficial to the restoration of macrobenthic communities.

[en] Penicillium citrinum F-5-5, a nuclease P1 high-producing strain with 978.6 U/ml in potato glucose medium, was derived from the original Penicillium citrinum CICC 4011 with ⁶⁰Co γ-rays irradiation mutation and then protoplasts fusion treatment. Culture components were optimized for the nuclease P1 production, and response surface methodology was applied for the critical medium components(carbon and nitrogen sources) which were preselected by Plackett-Burman design approach. Glucose, soluble starch and corn steep powder showed significant effects on production of nuclease. Central composite design was used for the optimization levels by software Minitab 15, and it showed that, the optimal values for the concentration of glucose, soluble starch and corn steep powder were 30.89, 42.46 and 11.60 g/L, respectively. With this medium,an enzyme activity of 1687.16 U/ml could be obtained theoretically. Using this optimized medium, an experimental enzyme activity of 1672.6 U/ml was reached. (authors)

[en] Highlights: • The FeS₂ spheres are embedded into the matrix of three-dimensional porous carbon. • The FeS₂/3DPC nanocomposites demonstrate excellent electrochemical performances. • The porous framework of 3DPC can supply an effective conductive network. The large volume variation and decomposition of pyrite iron sulfide (FeS₂) during the charge/discharge process are still a big issue limiting its application as electrode material for electrochemical energy storage. Herein, three-dimensional porous carbon (3DPC) decorated with FeS₂ nanospheres nanocomposites (FeS₂/3DPC) are developed as electrode material for supercapacitors and sodium ion batteries (SIBs) through a facile hydrothermal approach. The FeS₂/3DPC nanocomposites demonstrate much better electrochemical energy storage performances than pure FeS₂. The 50 %FeS₂/3DPC (FeS₂ content at 50% weight percent) shows an outstanding specific capacitance of 304F g⁻¹ at 2 A g⁻¹. Moreover, the 50 %FeS₂/3DPC as anode for Na⁺/Na half cell presents a high specific capacity of 770.3 mAh g⁻¹ at 0.02 A g⁻¹, and shows a remarkable rate performance and cyclic stability. The results prove that 3DPC as FeS₂ substrate can not only improve the conductivity of electrode material, but also effectively inhibit the volume collapse of FeS₂. The as-designed embedded structure and the synthesis technology should have a promising prospect for applying in electrochemical energy storage.

[en] Highlights: • Upconversion luminescence agent Er:YAG can enhance sonocatalytic activity of KNbO_3. • Harmless of narcotic drugs was achieved through sonocatalytic destruction. • Possible sonocatalytic destruction mechanism on narcotic drugs was proposed. - Abstract: A novel sonocatalyst, Er"3"+:Y_3Al_5O_1_2/KNbO_3 composite, was synthesized, and then, characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). In order to evaluate the sonocatalytic activity of prepared Er"3"+:Y_3Al_5O_1_2/KNbO_3 composite, the sonocatalytic degradation of ketamine, a kind of narcotic drug, was studied. In addition, some influencing factors such as mass ratio, heat-treated temperature and heat-treated time on the sonocatalytic activity of prepared Er"3"+:Y_3Al_5O_1_2/KNbO_3 powders and ultrasonic irradiation time on the sonocatalytic degradation of ketamine were examined by using GC–MS machine. The experimental results showed that the Er"3"+:Y_3Al_5O_1_2/KNbO_3 composite is a good sonocatalyst in the field of ultrasonic chemistry and the sonocatalytic degradation was an effective method for the innocent treatment of ketamine.

[en] The structural, electronic and magnetic properties of dual Cr atoms doped germanium anionic clusters, (n  =  3–14), have been investigated by using photoelectron spectroscopy in combination with density-functional theory calculations. The low-lying structures of are determined by DFT based genetic algorithm optimization. For with n  ⩽  8, the structures are bipyramid-based geometries, while cluster has an opening cage-like structure, and the half-encapsulated structure is gradually covered by the additional Ge atoms to form closed-cage configuration with one Cr atom interior for n  =  10 to 14. Meanwhile, the two Cr atoms in clusters tend to form a Cr–Cr bond rather than be separated. Interestingly, the magnetic moment of all the anionic clusters considered is 1 μ _B. Almost all clusters exhibit antiferromagnetic Cr–Cr coupling, except for two clusters, and . To our knowledge, the cluster is the first kind of transition-metal doped semiconductor clusters that exhibit relatively stable antiferromagnetism within a wide size range. The experimental/theoretical results suggest high potential to modify the magnetic behavior of semiconductor clusters through introducing different transition-metal dopant atoms. (paper)

[en] Highlights: • We measured the solubility of abietic acid in (ethanol + water) mixtures. • We correlated the SLE data using the Wilson, NRTL and λh equations. • We discussed the solution characteristics via the molar mixing enthalpy (H^E). -- Abstract: Using a laser monitoring observation technique, the solubility of abietic acid in (ethanol + water) mixtures was measured by a dynamic method at atmospheric pressure. The solubility of abietic acid increased with an increase of temperature and the concentration of ethanol. Experimental solubility data were correlated by means of the Wilson, NRTL and λh equations utilizing parameters derived from the (solid + liquid) equilibrium (SLE) data. The results showed that the three equations are suitable for description of the solubility data of abietic acid in the (ethanol + water) mixtures investigated