A Molten-Salt Method to Synthesize Co9 S8 Embedded, N, S Co-Doped Mesoporous Carbons from Melamine Formaldehyde Resins for Electrocatalytic Hydrogen Evolution Reactions.

We developed a molten salts process to prepare Co9 S8 nanoparticles (NPs) entrapped, S, N co-doped carbons. Cobalt chloride was used as the cobalt source. The melamine-formaldehyde (MF) resin provided the carbon source and nitrogen source, and thiourea provided sulfur source. In addition, common inorganic salts were added as templates to generate pores. The characterization results showed that the prepared materials contained high contents of N, S and Co, and were mesoporous composites. At the same time, the porosity of electrocatalyst depended on the type of salt and the mass ratio of precursor to salt, which further affected the electrocatalytic activity of hydrogen evolution reaction (HER). The best prepared catalyst showed excellent HER performance. The onset overpotential of the catalyst was low (33 mV) and had a small Tafel slope (61.1 mV dec-1 ), in addition to good stability in alkaline media.

Solubility Enhancement of Myricetin by Inclusion Complexation with Heptakis-O-(2-Hydroxypropyl)-ß-Cyclodextrin: A Joint Experimental and Theoretical Study.

Four cyclodextrins (CD) including ß-cyclodextrin (ß-CD), γ-cyclodextrin (γ-CD), heptakis-O-(2-hydroxypropyl)-ß-cyclodextrin (HP-ß-CD), and heptakis-O-(2, 6-di-O-methyl)-ß-cyclodextrin (DM-ß-CD) were used as solubilizer to study the solubility enhancement of myricetin. The results of the phase solubility study showed that the presence of CDs could enhance the solubility of myricetin by forming 1:1 complexes. Among all CDs, HP-ß-CD had the highest solubilization effect to myricetin. The concentration of myricetin could be 1.60 × 10-4 moL/L when the presence of HP-ß-CD reached 1.00 × 10-2 moL/L, which was 31.45 times higher than myricetin's aqueous solubility. Subsequently, the HP-ß-CD:myricetin complex was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). In order to get an insight of the plausible structure of the complex, molecular docking was used to study the complexation process of HP-ß-CD and myricetin. In the complex, the A ring and C ring of myricetin were complexed into the hydrophobic cavity of HP-ß-CD, while the ring B was located at the wide rim of HP-ß-CD. Four hydrogen bonding interactions were found between HP-ß-CD and -OH groups of the guest in the HP-ß-CD: myricetin complex. The complexation energy (△E) for the host-guest interactions was calculated with a negative sign, indicating the formation of the complex was an exergonic process. A 30-ns molecular dynamics simulation was conducted to the HP-ß-CD: myricetin complex. Calculation results showed that no large structural deformation or position change were observed during the whole simulation time span. The average root-mean-square deviation (RMSD) changes of the host and guest were 2.444 and 1.145 Å, respectively, indicating the complex had excellent stability.

Study on the accumulation characteristics and conduction trend of water environment risk from Taizihe River Basin, China.

The accumulation and conduction of water environmental risks is of great significance to the ecological safety of river basins. To resist the outbreak of water environmental risk events, it is important to control the risk during its production and conduction phases and cut the chain of risk conduction. Currently, there are rarely reports on the research of water environment risk conduction in river basins. In order to reveal the risk accumulation characteristics and conduction trend of water environment from Taizihe River Basin, this study tried to calculate the risk level coefficient, the comprehensive risk index, the probability and intensity of the risk conduction based on the risk energy theory, and reveal the risk conduction trend in the region. The results showed that the risk sources in the study area mainly include mining, petrochemicals, metallurgical industries and equipment manufacturing industries, and habitats were waters, cultivated land, forest land, grasslands and urban land. There were one region (R4) in the slight risk area, one region (R6) in the low risk area, two regions (R3 and R5) in the medium risk area, one region (R7) in the high risk area, and two regions in the very high risk area (R1 and R2). The upper reaches of the Taizihe River was the main risk accumulation area, and the middle and lower reaches were the main risk conduction release areas. The most important contributors to the risk were TN and NH3-N. The excess of nitrogen elements constituted the main risk source of node water quality. The highest risk during the wet and dry season occurred in the downstream section, and Tangmazhai, Xiaojiemiao, Sanchahe and Guchengzi all showed higher comprehensive risk values. This study breaks the previous idea of simple risk assessment, and observes the risk-shifting direction, which provides a theoretical and methodological support for watershed environmental risk research.

Facile formation of mesoporous structured mixed-phase (anatase/rutile) TiO2 with enhanced visible light photocatalytic activity.

A new mixed-phase (anatase/rutile) TiO2 with mesoporous structures and smaller crystal size (3-5 nm) was successfully synthesized by a facile sol-gel method at a lower calcination temperature (100 °C). Rhodamine B can be completely decomposed in the presence of the as-synthesized nanocomposite after only 60 minutes under visible light. Therefore it is believed to be a promising candidate for wastewater treatment.

[Intermolecular Interactions between Cytisine and Bovine Serum Albumin A Synchronous Fluorescence Spectroscopic Analysis and Molecular Docking Research].

Cytisine (Cy) is one of the alkaloids that exist naturally in the plant genera Laburnum of the family Fabaceae. With strong bioactivities, Cy is commercialized for smoking cessation for years. In this work, the study of intermolecular interactions between Cy and bovine serum albumin (BSA) was performed by applying fluorescence spectroscopic methods under simulated physiological conditions. The mechanism of fluorescence quenching of BSA by Cy was also studied. Parameters such as bathing temperature, time and solution pH were investigated to optimize the fluorescence quenching. The binding type, binding ratio and binding constant between BSA and Cy were calculated by using the Stem-Volmer equation. Experimental results indicated that Cy can quench the fluorescent emission of BSA statically by forming a 1 : 1 type non-covalent complex and the binding constant is 5.6 x 10(3) L x mol(-1). Synchronous fluorescence spectral research shows Cy may affect the fluorescence emission of Trp residues of BSA. Furthermore, molecular docking is utilized to model the complex and probe the plausible quenching mechanism. It can be noted that the hydrogen bindings and hydrophobic interactions between Cy and BSA change the micro-environment of Trp213, which leads to the fluorescence quenching of BSA.

Biological properties of nanostructured Ti incorporated with Ca, P and Ag by electrochemical method.

TiO2 nanotube arrays were synthesized on Ti surface by anodic oxidation. The elements of Ca and P were simultaneously incorporated during nanotubes growth in SBF electrolyte, and then Ag was introduced to nanotube arrays by cathodic deposition, which endowed the good osseointegration and antibacterial property of Ti. The bioactivity of the Ti surface was evaluated by simulated body fluid soaking test. The biocompatibility was investigated by in vitro cell culture test. And the antibacterial effect against Staphylococcus aureus was examined by the bacterial counting method. The results showed that the incorporation of Ca, P and Ag elements had no significant influence on the formation of nanotube arrays on Ti surface during electrochemical treatment. Compared to the polished or nanotubular Ti surface, TiO2 nanotube arrays incorporated with Ca, P and Ag increased the formation of bone-like apatite in simulated body fluid, enhanced cell adhesion and proliferation, and inhibited the bacterial growth. Based on these results, it can be concluded that the nanostructured Ti incorporated with Ca, P and Ag by electrochemical method has promising applications as implant material.

Enhanced cellular responses to titanium coating with hierarchical hybrid structure.

In this work, nano/micro hierarchical hybrid structured surface was prepared by fabricating a titania nanotube layer in plasma sprayed porous titanium coating (TC). In vitro human marrow stem cells (hMSCs) were employed for the evaluation of the biological properties of the anodized titanium coating with a hierarchical structure (HSTC). Significantly higher cell adhesion quantity (about 30% more) was found on the HSTC than that on the as-sprayed TC. The expressions of osteocalcin (OC) and osteopontin (OPN) for the HSTC were also detected to be about twice as high as those on the as-sprayed TC. The enhanced cell responses on the HSTC were explained by the improved protein adhesion resulted from the increased surface area and surface energy. Combining the advantages in the mechanical fixation and long-term stability of the plasma sprayed porous TC, the HSTC with a hierarchical structure may be a good candidate for hard tissue replacements, especially for load-bearing implants.

Influence of nanostructures on the biological properties of Ti implants after anodic oxidation.

Anodic oxidation was applied to produce nanostructures on the surface of titanium (Ti) implants. The bioactivity of the Ti implants was evaluated by simulated body fluid soaking test. The biocompatibility was investigated by in vitro cell culture test. The results showed that bone-like apatite was formed on the anodized Ti surface, but not on the as-polished Ti surface after immersion in simulated body fluid for 2 weeks. Cells cultured on the anodized Ti surface showed enhanced cell adhesion and proliferation, compared to those cultured on the as-polished Ti surface. Based on these results, it can be concluded that anodic oxidation improved the bioactivity and biocompatibility of Ti surface, which was attributed to the formation of nanostructures as well as the nanostructure induced high surface roughness and hydrophilicity.

Growth, photosynthesis and antioxidant responses of endophyte infected and non-infected rice under lead stress conditions.

An endophytic fungus was tested in rice (Oryza sativa L.) exposed to four levels of lead (Pb) stress (0, 50, 100 and 200 µM) to assess effects on plant growth, photosynthesis and antioxidant enzyme activity. Under Pb stress conditions, endophyte-infected seedlings had greater shoot length but lower root length compared to non-infected controls, and endophyte-infected seedlings had greater dry weight in the 50 and 100 µM Pb treatments. Under Pb stress conditions, chlorophyll and carotenoid levels were significantly higher in the endophyte-infected seedlings. Net photosynthetic rate, transpiration rate and water use efficiency were significantly higher in endophyte-infected seedlings in the 50 and 100 µM Pb treatments. In addition, chlorophyll fluorescence parameters Fv/Fm and Fv/Fo were higher in the infected seedlings compared to the non-infected seedlings under Pb stress. Malondialdehyde accumulation was induced by Pb stress, and it was present in higher concentration in non-infected seedlings under higher concentrations of Pb (100 and 200 µM). Antioxidant activity was either higher or unchanged in the infected seedlings due to responses to the different Pb concentrations. These results suggest that the endophytic fungus improved rice growth under moderate Pb levels by enhancing photosynthesis and antioxidant activity relative to non-infected rice.

[Analysis study of trace elements in abalone and sea cucumber].

Abalone and sea cucumbers are useful, which is related with trace elements in them. In the present paper, using high-pressure sealed nitrifying pots for digestion of samples, Orthogonal test was applied to the determination of 15 kinds of trace elements in abalone and sea cucumber such as Fe, Ca, Mg, Zn, Sr, Se, Hg, Cd etc by ICP-AES. The orthogonal table of L16 (4(4)) and experiment programs were designed. More information could be obtained with a small number of experimental times by combining chemistry with mathematical statistics, and the best experimental operation conditions could be chosen by square-error analysis. The method was simple, rapid, highly sensitive and accurate, but also features multi-element determination at the same time, with little environment pollution. The recovery rate of the method is in the range of 91.0%-110.0%, and relative standard deviations is less than 3.55%. The experimental results showed that both abalone and sea cucumber are of nutritional value of seafood, and are rich in Fe, Ca, Mg, Zn, Sr and other kinds of trace elements helpful to the human body. At the same time, because of severe environment pollution, seawater pollution should not be neglected. When seawater was polluted, hazardous substances were deposited in abalone or sea cucumber body with high levels of harmful heavy metals. Therefore, it should be a reminder that people must be careful to eat them.

[Determination of trace elements in the edible fungi by inductively coupled plasma atomic emission spectrometry].

In the present paper, samples were digested by high pressure digestion pots, reducing the loss of trace elements during the digestion process. The contents of trace elements in edible fungi such as Ca, Na, K, Mg, Mn, Ba, Fe, Co, Ge and Cu were determined by inductively coupled plasma atomic emission spectrometry. The relative standard deviation with high pressure digestion pots was 0.160-2.860, and that with wet method was 0.33%-3.49%, so it could be seen that the measurement precisions of the two methods were good, and the former was better. The measurement results with the two methods were checked by t-test, and the values in the range of 0.002 4-2.473 were lower than t(0.99, 9) (3.25). The measurement results showed that the two methods had no obvious differences, namely no system errors occurred. The recovery rates with high pressure digestion pots were in the range of 96.6% -103%. The method of high pressure digestion pots was suitable for the determination of trace elements in edible fungi with the advantages of being simple, rapid, sensitive, stable and accurate etc., and the results were satisfactory.

[Cu and Pb absorption and tolerance of Agrostis stolonifera and Festuca arundinacea].

This paper studied the seed germination rate, chlorophyll content, net photosynthetic rate, SOD activity, and Cu and Pb absorption of Agrostis stolonifera and Festuca arundinacea under Cu and Pb pollution. The results showed that Cu and Pb pollution had a significant effect on the seed germination rate of F. arundinacea. The chlorophyll content of F. arundinacea decreased dramatically under Pb and Cu-Pb pollution, while decreased slightly under Cu pollution. No significant effect of Cu and Pb was observed on the chlorophyll content of A. stolonifera. The SOD activity of A. stolonifera increased under 350 mg Cu x kg(-1) and all test concentrations of Pb, while that of F. arundinacea only increased under 700 mg Pb x kg(-1) and 350 mg Cu x kg(-1) + 1100 mg Pb x kg(-1). The net photosynthetic rate of F. arundinacea decreased more under Pb pollution than under Cu pollution, but that of A. stolonifera all decreased under Cu or Pb pollution. It was suggested that A. stolonifera was more tolerant in physiological characteristics to Cu and Pb pollution than F. arundinacea, while F. arundinacea was more tolerant to Cu than to Pb. The Cu absorption amount of F. arundinacea was relatively large, but did not increase with increasing Cu pollution. A. stolonifera had a high absorption ability of Pb, and the absorbed Pb amount was increased with increasing Pb pollution. A. stolonifera and F. arundinace could be the potential phytoremediation plants for Pb and Cu-polluted soil, respectively.

[Determination of trace elements in scallop].

The contents of eight trace elements Zn, Co, Fe, Mn, Mg, Ca, Cu and K in scallop were determined by ICP-AES and AAS using nitrifying method of high pressure nitrifying pot. The comparison between the results of two analysis methods was made, which proved no obviously differenct. The recoveries were 93.3%-102.8%, and the relative standard deviations were less than 1.60%. The experiment proved that scallop contains rich and useful trace elements, not only tastesgood and fresh, but also is essential supplemental elements that human body can not synthesize by itself.

[Determination of trace elements in different human hair and the comparison and research on living environment].

In the present paper, Chemometrics was applied to the determination of 20 kinds of trace elements in human hair by ICP-AES. The method was simple, rapid, highly sensitive and accurate. The determination of many elements could be performed at the same time. The recoveries of the method were in the range of 94.07%-107.6%, and the relative standard deviations were less than 3.49%. According to the results of 1 600 human hair samples with various ages from different regions, the influences of nutrition and environmental pollution upon human health were studied. Thereby, the comparison of and research on the living environment were carried out.

[Study of determination method of trace elements in white jade snail].

The contents of six trace elements, Ca, Mg, Fe, Zn, Cu and Co, in white jade snail were determined by ICP-AES and AAS using nitrifying method of high pressure nitrifying pot. The results of two analysis methods were compared, showing no obvious differences. The recoveries were 92.4%-103.0%, and the relative standard deviations were less than 2.98%. The experiment proved that white jade snail contains rich useful trace elements, and is a kind of green food with high nutrition.

[Determination of trace elements in beans by ICP-AES].

In this paper,the contents of trace elements in beans such as Ca, Mg, Mn, Sr, Fe, Co, Ni, Se and Ba were determined by ICP-AES uing nitrifying method of high pressure nitrifying pot, and compared with the results of wet method. The two methods showed no obvious differences. The method proves to be simple, rapid, highly sensitive, accurate and can be used to determine many elements at the same time. In addition, there was little environment pollution. Its recovery is 96.8%-102%, and relative standard deviation is 3.35%.

[Application of orthogonal test in determination of trace elements in wild vegetables by ICP-AES].

In this paper, orthogonal test was applied to determination of trace elements in wild vegetables just as Mn, Se, Cu, Fe, Mg and Zn by ICP-AES. It could provide many informations for us by less experimental times, and could choice the best experimental conditions by square-error analysis. It would be helpful for improving experimental accuracy. The method was simple, rapid, and possessed of highly sensitivity, good accuracy and determination of many elements at the same time, in addition little environment pollution. The recoveries of the method were in the range of 97.2%-103.3%, and relative standard deviations were less than 2.15%. The experimental results proved wild vegetables were valuable and nutritious food, they had rich trace elements.