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As an important part of die steels, hot-work die steels are mainly used to manufacture molds made of solid metal or high-temperature liquid metal from heating to recrystallization temperature. In view of the requirements for mechanical properties and service life for hot-work die steel, it is conducive to improve the thermal fatigue resistance, wear resistance, and oxidation resistance of hot work die steel. In this review, the main failure modes of hot-work die steel were analyzed. Four traditional methods of strengthening and toughening die steel were summarized, including optimizing alloying elements, electroslag remelting, increasing the forging ratio, and heat treatment process enhancement. A new nano-strengthening method was introduced that aimed to refine the microstructure of hot-work abrasive steel and improve its service performance by adding nanoparticles into molten steel to achieve uniform dispersion. This review provides an overview to improve the service performance and service life of hot work die steel. [ABSTRACT FROM AUTHOR]

Five transparent polyimide thin films with different proportions of 1,2,4,5-,pyromellitic dianhydride (PMDA) were made by copolymerization of 4,4'-(six fluoro isopropenyl) two phthalic anhydride (6FDA), 4,4'-two amino -2,2'-double three trifluoromethyl biphenyl (TFMB) and PMDA, and their properties were characterized. The results show that thermal stability and heat resistance are increased after the introduction of rigid monomers; the dielectric constant of the films is increased with the increase of PMDA content; homopolymer film has higher light transmission rate than copolymer films in visible light; tensile test shows that adding a small amount of PMDA, the tensile strength and elastic modulus of the film are increased, but when the content of PMDA is higher than 40%, the mechanical properties are decreased; the coefficient of thermal expansion of the films are decreased obviously while PMDA content is increased.

To deal with the difficulties in confirming the structure of neuron model and low forecast accuracy of grey theory, the grey situation decision theory based on new effect measure is proposed for the first time, and it is adopted to construct the structure topology of neural networks and determine the number of neurons in various layers and input-output computation of neurons. Then the grey neural network is taken as adaptive predictive inverse controller, which is implemented to the active control of jacket offshore platform. The simulation results show that the obtained grey neural network has strong robustness, and thus can be used to effectively control the displacement response on the top of jacket offshore platform under the random loads. [ABSTRACT FROM AUTHOR]

Reproductive toxicity research takes an important place in traditional Chinese medicine pre-clinical safety evaluation. Modern reproductive toxicity experiment includes drug-related miscarriage, fetal death, teratism, and adverse effects on fertility, genital system, embryonic development and fetus, which is different from contraindicated in pregnancy in traditional Chinese medicine theory. Now the three-phases reproductive toxicity study is the method mainly applied in traditional Chinese medicine reproductive toxicity evaluation. Besides that, alternative methods of whole embryos culture and embryonic stem cell test are also used in traditional Chinese medicine embryo toxicity evaluation. This article reviews research progress and pre-clinical evaluation on reproductive toxicity of traditional Chinese medicine.

The purpose of this study is to evaluate the embryotoxicity of alkaloids in Senecionis Scandentis Hebra on in vitro cultured mouse embryos. Mouse whole embryo culture (WEC) was applied in this study. Post-implantation (8.5 d) mouse embryos were isolated from their mothers, and cultured in medium of immediately centrifuged serum (ICS) with different concentrations of seneciphylline (target concentrations were 100, 50, 25 and 12.5 μg x mL(-1)) or senkirkine (target concentrations were 50, 25 and 12.5 μg x mL(-1)) for 48 h. After culturing completed, the development and organic morphodifferentiation of the cultured embryos were evaluated microscopically. Treatment with seneciphylline and senkirkine had adverse effects on the development and organic morphodifferentiation of embryos. The effect also had clear dose-response. Alkaloidals in Senecionis Scandentis Hebra had embryotoxicity on cultured embryos, which indicated that pregnant people exposed to Senecionis Scandentis Hebra may get potential risk on fetus.

Reviewing the literatures about adverse reactions induced by traditional Chinese medicine injections (TCMI) reported on CNKI from 1983 to 2013. Analyzing the causes of adverse reactions induced by TCMI from its quality standards. Provide ideas for improving security of TCMI and completing its quality standards. This review indicates that TCMI-induced adverse reactions have little relationship with the number of compositions, but have tight connection with chemical ingredients and solvents. Adverse reactions can be decreased by perfecting the quality standards of TCMI.

Pseudoallergic reactions of Qingkailing injection (QKLI) was assessed by vascular hyperpermeability which were indicated by ear blue staining in ICR mice after single intravenous injection of QKLI mixed with Evans blue (EB) and skin blue spot formation in SD rats after intradermal injection of QKLI and intravenous injection of EB. In addition, QKLI-induced histamine, VEGF, TNF-alpha release was measured after ICR mice received the single dosing of QKLI iv. The mild vascular hyperpermeability characterized by ear blue staining could be observed in mice after intravenous injection of QKLI and EB. Intracutaneous injection of 50 micro L of test solution containing QKLI (25,50 microL) in rat back skin caused obvious local vascular hyperpermeability at the injection sites so as to result the larger diameters of blue spots than that in negative control group (P <0. 01). QKLI induced a significant increase of VEGF and a slight elevation of histamine in mice after intravenous administration, while TNF-alpha showed no change after QKLI iv. The results in this study indicated that both intravenous injection and intracutanous injection of QKLI could induce vascular hyperpemeability so as to cause pseudoallergic reaction in mice and rats. QKLI-induced pseudoallergic reaction may be associated with the release of histamine and VEGF.