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The exploration of new efficient OER electrocatalysts based on nonprecious metals and the understanding of the relationship between activity and structure of electrocatalysts are important to advance electrochemical water oxidation. Herein, we developed an efficient OER electrocatalyst with nickel boride (Ni3B) nanoparticles as cores and nickel(II) borate (Ni-Bi) as shells (Ni-Bi@NB) via a very simple and facile aqueous reaction. This electrocatalyst exhibited a small overpotential of 302 mV at 10 mA cm−2 and Tafel slope of 52 mV dec−1. More interestingly, it was found that the OER activity of Ni-Bi@NB was closely dependent on the crystallinity of the Ni-Bi shells. The partially crystalline Ni-Bi catalyst exhibited much higher activity than the amorphous or crystalline analogues; this higher activity originated from the enhanced intrinsic activity of the catalytic sites. These findings open up opportunities to explore nickel(II) borates as a new class of efficient nonprecious metal OER electrocatalysts, and to improve the electrocatalyst performance by modulating their crystallinity. [ABSTRACT FROM AUTHOR]

Surface modification can improve biochar adsorption capacity. Biochars were produced from wheat straw through low-temperature pyrolysis at approximately 450°C, activated with hydrochloric acid (HCl), and coated with iron (FeCl36H2O) of different amounts. Results showed that activation with HCl and coating with iron can significantly increase biochar adsorption capacity. The increase after HCl treatment was very small at a high ratio of iron to biochar. The optimal ratio of iron to biochar for iron-coated biochar was 0.70. Adsorption capacity was calculated based on the amount of pure nitrogen or phosphorus. The maximum adsorption capacities were 2.47 and 16.58 mg g−1. The most effective pH values for nitrate and phosphate removal were 3 and 6, respectively. The active substance of the optimal-modified biochar (OMB) was amorphous FeOOH, and the structurewas the hydroxylated mineral surface of OMB in a water solution. The equilibrium pH of the adsorption solution was lower than 7 even when the initial pH of the solution was 11 becausechanged into,, and H3O+with the increase in pH. Adsorption experiments showed that OMB can be utilized to remove nitrate and phosphate from water. [ABSTRACT FROM PUBLISHER]

Objective: To study the correlation between 18F-FDG uptake and cell proliferation in cancer patients by meta-analysis of published articles. Methods: We searched PubMed (MEDLINE included), EMBASE, and Cochrane Database of Systematic Review, and selected research articles on the relationship between 18F-FDG uptake and Ki-67 expression (published between August 1, 1994-August 1, 2014), according to the literature inclusion and exclusion criteria. The publishing language was limited to English. The quality of included articles was evaluated according to the Quality Assessment of Diagnosis Accuracy Studies-2 (QUADAS-2). The correlation coefficient (r) was extracted from the included articles and processed by Fisher's r-to-z transformation. The combined correlation coefficient (r) and the 95% confidence interval (CI) were calculated with STATA 11.0 software under a random-effects model. Begg's test was used to analyze the existence of publication bias and draw funnel plot, and the sources of heterogeneity were explored by sensitivity and subgroup analyses. Results: According to the inclusion and exclusion criteria, 79 articles were finally included, including 81 studies involving a total of 3242 patients. All the studies had a combined r of 0.44 (95% CI, 0.41-0.46), but with a significant heterogeneity (I2 = 80.9%, P<0.01). Subgroup analysis for different tumor types indicated that most subgroups showed a reduced heterogeneity. Malignant melanoma (n = 1) had the minimum correlation coefficient (-0.22) between 18F-FDG uptake and Ki-67 expression, while the thymic epithelial tumors (TETs; n = 2) showed the maximum correlation coefficient of 0.81. The analytical results confirmed that correlation between 18F-FDG uptake and Ki-67 expression was extremely significant in TETs, significant in gastrointestinal stromal tumors (GISTs), moderate in patients with lung, breast, bone and soft tissue, pancreatic, oral, thoracic, and uterine and ovarian cancers, average in brain, esophageal and colorectal cancers, and poor in head and neck, thyroid, gastric and malignant melanoma tumors. Subgroup analysis indicated that positron emission tomography (PET) or PET/CT imaging technology or Ki-67 and standardized uptake value (SUV) measurement technology did not significantly affect the results of r values, and Begg's test showed no significant publication bias. Conclusion: In cancer patients, 18F-FDG uptake showed a moderate positive correlation with tumor cell proliferation. Different tumor types exhibited varied degree of correlation, and the correlation was significant in TETs and GSTs. However, our results need further validation by clinical trials with a large sample of different tumor types. [ABSTRACT FROM AUTHOR]

In order to understand the characteristics of coarse slime rod-grinding and flotation process, improve the economic and technical indicators of coarse slime repreparattion, the paper took the tailing of TBS from Dawukou-Jinneng Coking Coal Preparation Plant as a study object. Firstly, a series of grinding experiments were conducted in laboratory, the best slurry concentration, medium composition, mill speed and medium filling rate was determined, and then by adjusting the grinding time, five groups of different particle size and dissociation products were obtained. The result showed that the product with 12 min grinding time had more appropriate size composition and better dissociation, by repreparation flotation could get clean coal with the ash content 12.92% and the production rate of the cleaned coal would be 33. 89%. In the analysis of density and particle size of floatation concentrate, middings, tailings, part of slime dissociation was inadequate, floating ability of coarse slime of low ash too poor, resulting low recovery rate, high ash slime by entrainment into the high coal ash. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effects of foliar spraying of three kinds of compound agents [plant polysaccharides (P1), plant polysaccharides plus 5-aminolevulinic acid (P2), and plant polysaccharides plus 5-aminolevulinic acid and dimethylpiperidinium chloride (P3)] at the initial flowering stage of winter wheat on its yield components, sucrose content, soluble sugar content, the accumulation and translocation of dry matter, nitrogen and phosphorus. The grain number per spike and kilo-grains mass of winter wheat increased with the spray of the compound agents. The grain yield increased by more than 8. 5% compared with the control. Within 20 days after spraying the three compound agents, the sucrose content of flag leaf had an obvious increase. Compared with the control, P1 and P3 increased the soluble sugar content by more than 4. 5% and 11. 0%, respectively. P3 enhanced the accumulations of post-anthesis dry matter, nitrogen and phosphorus by 48.5%, 116.9% and 18.1%, respectively. Correspondingly, contributions of accumulated post-anthesis dry matter and nutrient to grain yield increased significantly. Whereas, the contribution of translocated pre-anthesis nutrient to grain yield in P3 treatment was smaller than in the other treatments. The high yield of winter wheat was related to the regulation of photosynthetic product supply in vegetative organ, the increased soluble sugar content in grain, and the accumulation of post-anthesis dry matter and nutrient regulated by the plant polysaccharides- containing compound agent. [ABSTRACT FROM AUTHOR]

Abstract: A mild, transition metal-free, and environmentally benign NBS-promoted C–N bond formation of N-heterocycles is successfully demonstrated. A series of heterocyclic derivatives are readily prepared under mild conditions in moderate to good yields. [Copyright &y& Elsevier]

A field experiment was conducted to study the effects of foliar spraying three compound agents [plant polysaccharides (P1), plant polysaccharides and 5-aminolevulinic acid (P2), and plant polysaccharides and 5-aminolevulinic acid and dimethylpiperidinium chloride (P3)] at the initial flowering stage of soybean on its leaf chlorophyll content, photosynthesis and transpiration, dry matter accumulation and allocation, and grain yield. Within 35 days after spraying the three compound agents, the leaf chlorophyll content had obvious increase, and its decreasing trend with plant growth had somewhat delay. Compared with the control, spraying P1 and P3 increased the leaf photosynthetic rate and water use efficiency by more than 13. 2% and 10. 3%, respectively. With the spraying of the three compound agents, the dry matter accumulation in aerial part increased, and the allocation of dry matter from leaf to pod was also enhanced, with the contribution of post-anthesis assimilates to grain yield increased by more than 17. 1%. The 100-grain mass and the pods and seeds per plant increased significantly after spraying P1 and P3, but had no significant increase after spraying P2. The grain yield of soybean treated with the three compound agents increased by more than 5. 9%, compared with the control. This study showed that the three plant polysaccharide compound agents could increase the leaf chlorophyll content, delay the leaf-senescence, improve the leaf photosynthetic capacity and water status, effectively control the dry matter accumulation and post-anthesis assimilates allocation, and increase the grain yield of soybean. [ABSTRACT FROM AUTHOR]

Two copper(II) complexes of disubstituted 2,2'-bipyridine (bpy = 2, 2'-bipyridine) with tetraalkylammonium groups, [Cu(L1)2Br](ClO4)5·2H2O (1) and [Cu(L2)2Br](ClO4)5·H2O (2) (L1 = [4, 4'-(Et3NCH2)2-bpy]2+, L2 = [4, 4'-((n-Bu)3NCH2)2-bpy]2+), have been synthesized and characterized. X-ray crystallographic study of 1 indicates that Cu(II) is a distorted trigonal bipyramidal or square pyramid. DNA binding of both complexes was studied by UV spectroscopic titration. In the presence of reducing reagents, the cleavage of plasmid pBR322 DNA mediated by both complexes was investigated and efficient oxidative cleavage of DNA was observed. Mechanistic study with reactive oxygen scavengers indicates that hydrogen peroxide and singlet oxygen participate in DNA cleavage. [ABSTRACT FROM AUTHOR]

Abstract: Two novel zinc complexes of disubstituted 2,2′-bipyridine with ammonium groups, [Zn(L1)3](ClO4)8·3H2O (1) and [Zn(L2)3](ClO4)8 (2) (L1 =[4,4′-(Me2NHCH2)2-bpy]2+, L2 =[5,5′-(Me2NHCH2)2-bpy]2+, bpy=2,2′-bipyridiyl) were synthesized as artificial nucleases. The outside electrostatic binding interaction between these complexes and calf thymus DNA was confirmed by UV and CD spectroscopies. Even at low concentration (2.0×10−4 M), both complexes can effectively cleave supercoiled plasmid DNA to nicked form, giving hydrolysis rate constants of 1.84×10−5 and 2.16×10−5 s−1, respectively. [Copyright &y& Elsevier]

Abstract: Expanded graphite was prepared using the fine flake graphite that could go straight through 160 μm mesh as raw material, using acetic anhydride as inserting agent and potassium dichromate as oxidant. The best process conditions are as follows: m (fine graphite):m (acetic anhydride):m (concentrated sulfuric acid):m (potassium dichromate)=1:1.0:3.1:0.6, reaction time is 50 min and reaction temperature is 45 °C. The expanded graphite prepared using the fine flake graphite that could go straight through a 160 μm mesh has many good qualities, such as low mass, small pellet, resists high temperature and resists pressure. The expanded graphite is also an excellent material for antistatic and anti-electromagnetic. [Copyright &y& Elsevier]

Abstract: Sulfur-free exfoliated graphite at a low exfoliation temperature was prepared from graphite intercalation compounds (GICs) synthesized chemically with different consumption of insertion reagents and oxidants. The effects of their consumption on the synthesis of GICs and of exfoliation temperature on exfoliation volume were studied. The exfoliation volume was 350 ml/g at exfoliation temperature of 200 °C in the best process condition. These results revealed a marked development of the pores in Exfoliated graphite. [Copyright &y& Elsevier]

Interesting conditions are developed for the alkylation of N-heterocycles with β-diketones. [ABSTRACT FROM AUTHOR]