Characterization,Mechanism and Control Measures of V Segregation in Continuous Casting Billet of C-Mn Steel

Metallurgical and Materials Transactions B - To eliminate V segregation, which significantly deteriorates the homogeneity of continuous casting steel billets, V segregation in the C-Mn steel billet...     

聚合物/层状硅酸盐粘土纳米复合材料的阻燃性能研究

综述了国内外近年来对蒙脱土的有机改性、聚合物/层状硅酸盐纳米复合材料的阻燃性能及其机理研究动向.     

电子辐照PVA/CMC共混水凝胶的成胶研究

本试验利用电子辐照PVA/CMC共混水凝胶,通过外观透明度、凝胶分数、溶胀度和红外光谱分析,研究了样品中结构的变化与外观透明度、凝胶分数和溶胀度的关系,以及辐照剂量对样品中结构和性能的影响.结果表明,不同比例的PVA与相同比例的CMC组成的共混水凝胶,经电子辐照后呈现不同的宏观特性.辐照样品萃取后得到的凝胶比萃取前的混合凝胶拥有更强的吸水性,表明辐照PVA/CMC共混凝胶形成了网状结构凝胶.几种竞争反应导致不同辐照剂量下混合凝胶中凝胶含量随PVA含量的变化变得复杂.辐照后样品的红外光谱分析显示,辐照使凝胶中部分仲醇中C上链接的H原子被取代而转变为叔醇,从而产生交联.     

Regulatory Mechanisms of Mitogen-Activated Protein Kinase Cascades in Plants: More than Sequential Phosphorylation

Mitogen-activated protein kinase (MAPK) cascades play crucial roles in almost all biological processes in plants. They transduce extracellular cues into cells, typically through linear and sequential phosphorylation and activation of members of the signaling cascades. However, accumulating data suggest various regulatory mechanisms of plant MAPK cascades in addition to the traditional phosphorylation pathway, in concert with their large numbers and coordinated roles in plant responses to complex ectocytic signals. Here, we highlight recent studies that describe the uncanonical mechanism of regulation of MAPK cascades, regarding the activation of each tier of the signaling cascades. More particularly, we discuss the unusual role for MAPK kinase kinases (MAPKKKs) in the regulation of MAPK cascades, as accumulating data suggest the non-MAPKKK function of many MAPKKKs. In addition, future work on the biochemical activation of MAPK members that needs attention will be discussed.     

Synthesis and near-infrared luminescent properties of some ruthenium complexes

A series of seven ruthenium complexes with different ligands were synthesized and their optical, electrochemical and photoluminescent properties were characterized. Electroluminescent properties of these complexes were further evaluated using a light-emitting electrochemical cell with a configuration of indium tin oxide (ITO)/complex (100 nm)/Au (100 nm). Tunable photoluminescence (PL) and electroluminescence (EL) from 630 to 1040 nm have been achieved by adjusting the LUMO and HOMO levels of ruthenium complexes.     

Preparation of Ofloxacin Poly(Glycidyl Methacrylate-Co-Ethylenedimethacrylate) (PGMA/EDMA) Molecularly Imprinted Microspheres and Their Application to the Analysis of Quinolones in Milk

A series of novel ofloxacin-imprinted polymers have been prepared using poly(glycidyl methacrylate-co-ethylenedimethacrylate) (P_GMA/EDMA) particles as a support and their recognition abilities evaluated. Several factors that are known to influence the rebinding of the imprinted polymers were investigated, including the pH and water content of the adsorbed solutions. The binding capabilities of the materials were also evaluated. The resulting P_GMA/EDMA molecularly imprinted polymers were used as selective solid phase extraction sorbents for the simultaneous determination of three different quinolones in milk, with the results revealing high levels of selectivity. The use of 10 % methanol–water as washing solution together with 2 % trifluoroacetic acid–acetonitrile as an elution solution allowed for the three different quinolones to be selectively extracted from the milk samples. Furthermore, all of the matrix interference factors were eliminated simultaneously, whereas the enrichment factors were >234. The quantification limit was determined to be 1.00 ng/mL using an ultraviolet detector, and the recovery was in the range of 81.8–102.0 % with a relative deviation of <9.6 %.     

Relationship between N-nitrosodiethylamine formation and protein oxidation in pork protein extracts

The relationship between protein oxidation and N-nitrosodiethylamine (NDEA) formation was assessed. Packaged fresh minced pork was stored at 2 ± 1 °C for 0, 4, 7, and 10 days. Myofibrillar protein (MP), sarcoplasmic protein (SP), and muscle homogenate were obtained from the stored minced pork and allowed to react with sodium nitrite at 80 °C for 1 h. The relationship between NDEA formation and indexes of protein oxidation was assessed by principal component analysis. The formation of NDEA in meat was correlated with protein and lipid oxidation. Lipid oxidation promoted the formation of NDEA and was positively correlated with protein oxidation. Carbonyl compounds from oxidized MP and free amines from dissociated SP promoted NDEA formation. Therefore, the effect of protein oxidation on NDEA formation depends on the type of protein and its oxidation products.     

Glucose Metabolism,Neural Cell Senescence and Alzheimer’s Disease

Alzheimer’s disease (AD), an elderly neurodegenerative disorder with a high incidence and progressive memory decline, is one of the most expensive, lethal, and burdening diseases. To date, the pathogenesis of AD has not been fully illustrated. Emerging studies have revealed that cellular senescence and abnormal glucose metabolism in the brain are the early hallmarks of AD. Moreover, cellular senescence and glucose metabolism disturbance in the brain of AD patients may precede amyloid-β deposition or Tau protein phosphorylation. Thus, metabolic reprogramming targeting senescent microglia and astrocytes may be a novel strategy for AD intervention and treatment. Here, we recapitulate the relationships between neural cell senescence and abnormal glucose metabolism (e.g., insulin signaling, glucose and lactate metabolism) in AD. We then discuss the potential perspective of metabolic reprogramming towards an AD intervention, providing a theoretical basis for the further exploration of the pathogenesis of and therapeutic approach toward AD.