Generalized arcwise-connected functions and characterizations of local-global minimum properties

In this paper, new classes of generalized convex functions are introduced, extending the concepts of quasi-convexity, pseudoconvexity, and their associate subclasses. Functions belonging to these classes satisfy certain local-global minimum properties. Conversely, it is shown that, under some mild regularity conditions, functions for which the local-global minimum properties hold must belong to one of the classes of functions introduced.Dedicated to R. BellmanThe authors are indebted to I. Kozma, N. Megiddo, and A. Tamir for valuable discussions and to S. Schaible for valuable remarks. This research was partially supported by the Fund for the Encouragement of Research at the Technion.     

N-氧化吡啶-2-甲醛衍生物的配合物研究(Ⅰ)——与二胺生成的双Schiff碱铜配合物的合成和晶体结构

报道了N-氧化吡啶-2-甲醛(Pio)与乙二胺(en)及1,3-丙二胺(tn)生成的双Schiff碱Cu(Ⅱ)配合物([Cu(Pioen)H_2O](ClO_4)_2和[Cu(Piotn)(H_2O)_2](ClO_4)2)的合成和晶体结构。晶体[Cu(Pioen)H_2O_3(ClO_4)_2属正交晶系,空间群P2_12_12_2,α=7.9534(19),b=7.6768(48),c=26.1037(189),Z=4,R=0.077 1,R_w=0.0771。晶体[Cu(Piotn)-(H_2O)_2](ClO_4)_2属正交晶系,空间群P~(nam),α=7.1360(24)。b=13.7887(42),0=22.2556(81),Z=4,R=0.0491,R_w=0.0491。结构由Patterson函数及Fourier合成法解出,经全矩阵最小二乘法修正至收敛。     

Synthesis and catalytic application of octahedral lewis base adducts of dichloro and dialkyl dioxotungsten(VI)

Complexes of the composition W(O)(2)(Cl)(2)L(2) and W(O)(2)(R)(2)L(2) (R = Me, Et; L(2) = bidentate Lewis base ligand) have been prepared and are fully characterized (including an exemplary X-ray crystal structure of W(O)(2)(Cl)(2)(4,4'-di-tert-butyl-2,2'-bipyridine)). This latter compound crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 8.3198(1) A, b = 13.3224(2) A, c = 18.0415(2) A, and Z = 4. The title complexes are applied as catalysts in olefin epoxidation catalysis with tert-butyl hydroperoxide (TBHP) as the oxidizing agent. The W(VI) complexes display only moderate turnover frequencies but can be reused several times without loss of catalytic activity. The highest activity can be achieved at reaction temperatures of ca. 90 degrees C. Chloro derivatives are somewhat more active than alkyl complexes, and sterically less crowded complexes show also higher activities than their congeners with bulky ligands L(2). Kinetic examinations show that the catalyst formation is the rate determining step and it is observed that tert-butyl alcohol, the byproduct of the epoxidation reaction, acts as a competitor for TBHP, thus lowering the reaction velocity during the course of the reaction but not irreversibly destroying the catalyst.     

Lipid rafts are important for the association of RANK and TRAF6

Rafts, cholesterol- and sphingolipid-rich membrane microdomains, have been shown to play an important role in immune cell activation. More recently rafts were implicated in the signal transduction by members of the TNF receptor (TNFR) family. In this study, we provide evidences that the raft microdomain has a crucial role in RANK (receptor activator of NF-kappaB) signaling. We found that the majority of the ectopically expressed RANK and substantial portion of endogenous TRAF2 and TRAF6 were detected in the low-density raft fractions. In addition, TRAF6 association with rafts was increased by RANKL stimulation. The disruption of rafts blocked the TRAF6 translocation by RANK ligand and impeded the interaction between RANK and TRAF6. Our observations demonstrate that proper RANK signaling requires the function of raft membrane microdomains.     

两性高分子与小分子及大分子的相互作用（下）

2 两性高分子与染料及表面活性剂的相互作用文献中对阳离子聚电解质、阴离子聚电解质及非离子性高分子与染料、去污剂、表面活性剂等小分子物质的相互作用有较多报道,而有关两性高分子与这些小分子物质相互作用的报道极少。本节就合成两性高分子与染料等小分     

新型阳离子(苯乙烯—丙烯酰胺)共聚物的研究 Ⅱ.阳离子(苯乙烯——丙烯酰胺)共聚物与染料的相互作用

以P(St-Am·MG)对染料活性艳红(X-3B)溶液进行絮凝试验,考察了高聚物剂量及外加盐对絮凝效果的影响,并与无疏水基团的阳离子聚丙烯酰胺PAm·MG的絮凝能力进行了比较。发现絮凝体系无外加盐时,高聚物与染料的作用主要是通过静电力;有外加盐时,高聚物的电荷受到屏蔽,高分子链卷曲,PAm·MG的絮凝效果受到较大影响。而P(St-Am·MG)与X-3B之间存在疏水相互作用,受影响较小,此时P(St-Am·MG)的絮凝性能优于PAm·MG。用平衡渗析法研究了不同温度时甲醇和脲存在下P(St-Am·MG)与X-3B相互作用的热力学。证明了它们之间确实存在疏水相互作用。     

GENERATION OF FREE RADICALS DURING PHOTOSENSITIZATION OF HYPOCRELLIN A AND THEIR EFFECTS ON CARDIAC MEMBRANES

Hypocrellin A (HA), a peryloquinone derivative, has recently been isolated from a fungus Hypocrella bambusae. This lipid soluble pigment, in combination with phototherapy, has been used to treat many skin diseases including the keloids caused by scalding and burns. We have studied the effects of photosensitized HA on biomembranes using pig heart microsomes. Photosensitization of HA was found to peroxidize the membrane lipids in the cardiac microsomes. The photodamage imposed by HA depended not only on the concentration of HA but also on the time of irradiation and pH of the system. Superoxide dismutase (SOD), ascorbic acid, beta-carotene and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) inhibited the lipid peroxidation approximately 50, approximately 50, approximately 30 and approximately 97%, respectively. Spin trapping in combination with EPR spectroscopic techniques was used to identify the reactive free radicals during the photoreaction. Formation of superoxide anion radical, (O2-.), was identified by the SOD-inhibitable DMPO-O2- EPR spectrum. Both SOD and ascorbic acid inhibited the EPR signal intensity in a dose-dependent manner with rate constants of 6.78 x 10(8) M-1 s-1 and 1.82 x 10(4) M-1 s-1, respectively. The lifetime of O2-., under these conditions, was found to be 1.1 s. Photoirradiation of HA yielded a HA free radical with a g = 2.002 which was not suppressed by SOD but in the presence of reductants such as ascorbic acid and catechol the septum was completely suppressed. The increase of the EPR signal intensity and malondialdehyde formation with increasing pH may be due, in part, to the production of predominant *HA- species at high pH which would be more reactive with oxygen to yield O2-.. These results indicate that the lipid peroxidation of the cardiac membranes observed during photooxidation of HA may arise, in part, from the interaction of membrane lipids with reactive species of oxygen and HA free radical produced during the photo-irradiation.     

On the expression of uncertainty intervals in engineering

The paper summarizes the terminology of the statistics and probability disciplines as they pertain to uncertainty quantification in engineering.