An application of Furuta inequality and its best possibility

This paper shows the best possibility for outer exponents of some inequalities under some conditions, and a counter example is obtained.     

Minimizing the weighted number of tardy jobs on parallel processors

We present a branch-and-bound algorithm to minimize the weighted number of tardy jobs on either identical or non-identical processors. Bounds come from a surrogate relaxation resulting in a multiple-choice knapsack. Extensive computational experiments indicate problems with 400 jobs and several machines can be solved quickly. The results also indicate what parameters affect solution difficulty for this algorithmic approach.     

Highly enantioselective Michael addition of α,α-disubstituted aldehydes to maleimides catalyzed by new primary amine-squaramide bifunctional organocatalysts

New bifunctional primary amine-squaramides catalyzed asymmetric Michael addition reaction of α,α-disubstituted aldehydes to maleimides has been developed. This organocatalytic asymmetric reaction provides easy access to functionalized succinimides with a broad substrate scope. Both enantiomers of desired succinimide derivatives were obtained in good to excellent yields (up to 98%) with excellent enantioselectivities (up to >99%?ee).     

Amperometric determination of organophosphate pesticides using a acetylcholinesterase based biosensor made from nitrogen-doped porous carbon deposited on a boron-doped diamond electrode

Microchimica Acta - The authors describe an amperometric biosensor for the determination of organophosphate pesticides (OPs) via inhibition of the enzyme acetylcholinesterase (AChE). The enzyme was...     

聚环氧乙烷/埃洛石纳米管复合材料的热稳定性和燃烧性质

采用熔融共混法制备了聚环氧乙烷(PEO)/埃洛石纳米管(HNTs)复合材料,重点研究了HNTs含量对PEO/HNTs复合材料的微观结构、热稳定性及燃烧性质的影响。结果表明,在熔融共混条件下,不同含量的表面未经任何处理的HNTs以纳米尺度均匀分散于PEO基体中;随着HNTs含量的增加,复合材料的热稳定性显著增加。氧指数和水平燃烧测试结果均表明随着HNTs含量的增加,复合材料的阻燃能力有较大提高。     

一种两性三元共聚物的合成

选用聚乙二醇二丙烯酸酯(PEGDA)为扩链剂,以丙烯酰胺(AM)、2-甲基-2-丙烯酰胺基丙磺酸(AMPS)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为主单体,采用水溶液聚合方法合成了两性三元共聚物AM/AMPS/DMC;测定了共聚物的性能,并利用红外光谱研究了其分子结构.结果表明,所合成的共聚物具有良好的耐酸和高温稳定性,以及高抗剪切率.     

无溶剂条件下α-羟基磷酸酯的合成

在无溶剂条件下,以碳酸钾做催化剂,芳香醛与亚磷酸酯在室温下通过研磨,合成了一系列磷酸酯类化合物.该反应条件温和,操作简单,时间短,对环境友好,是一种绿色的合成方法.产物结构经IR,MS,1HNMR等方法表征.     

Langmuir-Blodgett film of p-tert-butylthiacalix[4]arene modified glassy carbon electrode as voltammetric sensor for the determination of Hg(II)

The π-A isotherms and UV-vis spectra of the transferred films suggested that the monolayer of p-tert-butylthiacalix[4]arene can coordinate with Hg²⁺ at the air-water surface. From these observations, a glassy carbon electrode coated with Langmuir-Blodgett film of p-tert-butylthiacalix[4] arene as a new voltammetric sensor is designed for the determination of trace amounts of Hg²⁺. Compared with bare glassy carbon electrode and modified glassy carbon electrode using direct coating method, the Langmuir-Blodgett film-modified electrode can greatly improve the measuring sensitivity of Hg²⁺. Under the selected conditions, the Langmuir-Blodgett film-modified electrode in 0.1 mol L⁻¹ H₂SO₄ + 0.01 mol L⁻¹ KCl solution shows a linear voltammetric response for Hg²⁺ in the range of 5.0 × 10⁻¹⁰ to 1.5 × 10⁻⁷ mol L⁻¹, with a detection limit of 2.0 × 10⁻¹⁰ mol L⁻¹. The proposed method was also applied to determine Hg²⁺ in water samples (tap, lake and river water). In addition, the fabricated electrode exhibited a distinct advantage of simple preparation, non-toxicity, good reproducibility and good stability.     

Cloning and Identification of a Novel P-II Class Snake Venom Metalloproteinase from <Emphasis Type="Italic">Gloydius halys</Emphasis>

Ahpfibrase was a new snake venom metalloproteinase (SVMP) which was cloned from Gloydius halys. The cDNA sequence with 1,891 base pairs encodes an open reading frame of 477 amino acids which includes a 17 amino acid signal peptide, plus a 171 amino acid segment of zymogen-like propeptide, a metalloproteinase domain of 200 amino acids, a spacer of 16 amino acids, and a disintegrin-like peptide of 73 amino acids. The metalloproteinase domain contained a conserved signature zinc-binding motif HEXXHXXGXXH in the catalytic region and a methionine-turn CIM. To determine the activity of ahpfibrase, the coding region including both the metalloproteinase domain and disintegrin region was amplified by PCR, inserted into the pET25b(+) vector, and expressed in Escherichia coli. The recombinant protein was recovered from inclusion bodies with 8 M urea and refolding was performed by fed-batch dilution method, and purified recombinant ahpfibrase showed the fibrinolytic activity and platelet aggregation–inhibition ability.