Mossbauer spectra of Fe-57 in a thick film of YBa2(Cu0.97Fe0.03)(3)O7-x irradiated by a large dose of gamma-rays

Mossbauer spectra of Fe-57 in a thick film YBa2(Cu0.97Fe0.03)(3)O7-x irradiated by a large dose of gamma-rays from Co-60 have been measured. The variation of the relative intensities of some subspectra of Fe-57 in the. Mossbauer spectra of the thick film YBa2(Cu0.97Fe0.03)(3)O7-x after irradiation can be observed. This variation indicates that the change of the coordination environment around some Fe atoms in the lattice occurs due to irradiation. The relative intensity of subspectrum D1(Fe) at the Cu(1) site decreases and that of subspectrum D4(Fe) at the Cu(1) site increases. This may be because of the possible oxygen atom hopping between the coordination environments of D1(Fe) and D4(Fe) in the lattice caused by irradiation. The effect of irradiation on the coordination environment around the Fe atom at the Cu(2) site is not appreciable. (C) 1997 Elsevier Science B.V.

α-羰基烯酮环二硫代缩醛化学(XXXVI)──β,β-1,3-亚丙二流基-α,β-不饱和芳酮与Grignard试剂加成物的硅胶催化分解反应

以β，β-1，3-亚丙二硫基-α，β-不饱和芳酮2与烯丙基或等基Grfenard试剂可选择性地进行1，2-加成得醇3、4，在硅胶G的催化下，醇3、4可分解生成β，γ-不饱和芳酮5、6．并对该分解反应的机制进行了初步探讨.

Eu~(3+)在YAG中的发光性能及Eu~(3+)、Bi~(3+)间的能量传递

ＹＡＧ作为一种新型的功能材料已引起了人们极大的兴趣，我们采用溶胶、凝胶法合成了ＹＡＧ：Ｅｕ和ＹＡＧ：Ｅｕ，Ｂｉ，研究了Ｅｕ３＋在ＹＡＧ中的发光及Ｅｕ３＋，Ｂｉ３＋间的能量传递。１实验部分将纯度９９．９９％Ｙ２Ｏ３，Ｅｕ２Ｏ３和Ｂｉ２Ｏ３分别溶于ＧＲ级ＨＮＯ３中，配制成一定浓度的溶液，然后以Ｙ（ＮＯ３）３，Ｅｕ（ＮＯ３），Ｂｉ（ＮＯ３）３和Ａｌ（ＮＯ３）３为初始原料，按（Ｙ１－ｘＥｕｘ）３ＡＬ５Ｏ１２和（Ｙ１－ｘ－ｙＥｕｘＢｉｙ）３Ａｌ５Ｏ１２化学式量配比，充分混匀后加入柠檬酸，缓慢蒸干，在４００℃灼烧２ｈ

Gas permeability in polyimides from oxydianiline and isomeric thiaphthalic dianhydride or 1,4-bis(dicarboxyphenoxy) benzene dianhydride

The gas permeability and permselectivity properties were investigated of polyimides, prepared from 3,3',4,4'- and 2,2',3,3'-thiaphthalic dianhydride (p-TDPA and m-TDPA, respectively), or 1,4-bis(3,4-dicarboxyphenoxy)- and 1,4-bis(2,3-dicarboxyphenoxy) benzene dianhydride (p-HQDPA and m-HQDPA, respectively), and 4,4-oxydianiline. The polyimides prepared from meta-dianhydrides, which have lower chain-segment packing density, possess higher permeability and lower permselectivity than those prepared from para-dianhydrides. Copyright (C) 1996 Elsevier Science Ltd.

STATISTICAL THERMODYNAMICS IN THE FRAMEWORK OF THE LATTICE FLUID MODEL .3. BINARY MIXTURE OF POLYDISPERSE POLYMERS OF SPECIAL DISTRIBUTION WITH STRONG-INTERACTIONS

For a binary mixture of polydisperse polymers with strong interactions, the free energy, the equation of state, the chemical potentials and the spinodal are formulated on the basis of the lattice fluid model. Further, the spinodal curves for the system wi

掺Ce~（3＋）、Tb~（3＋）的四硼酸铝钇的发光特性

本文采用固相反应法合成了一系列掺Ｃｅ￣（３＋）、Ｔｂ￣（３＋）的四硼酸铝钇（Ｙ＿（１－ｘ－ｙ）Ｃｅ＿ｘＴｂ＿ｙＡｌ（ＢＯ＿３）＿４）磷光体。测定了它们的结构、属于三方晶系、空间群Ｒ＿（３２）、Ｌｎ￣（３＋）离子处于六个氧形成的三棱柱中。测定了磷光体中Ｃｅ￣（３＋）、Ｔｂ￣（３＋）和Ｃｅ￣（３＋）－Ｔｂ￣（３＋）共掺时的光谱，观察到Ｃｅ￣（３＋）、的Ｓｔｏｋｅｓ位移相当小（～１７００ｃｍ￣（－１））、Ｔｂ￣（３＋）的能级劈裂较明显和Ｃｅ￣（３＋）能将能量传递给Ｔｂ￣（３＋），测定了磷光体中Ｃｅ￣（３＋）、的荧光寿命，探讨了Ｃｅ￣（３＋）－Ｃｅ￣（３＋）之间的能量传递。

五磷酸钆晶体中Sm~(3+)的光谱

本文研究了 GdP_5O0_(14):Sm~(3+)(GdPP:Sin)晶体的激发光谱和荧光光谱。Sm~(3+)离子的4~G_5/2→~6H_7/2跃迁的荧光发射(594nm)很强,荧光强度是 Sm~(3+)离子浓度的函数。Sm~(3+)—Sm~(3+)离子间有较严重的浓度猝灭现象。讨论了 Gd~(3+)—Sm~(3+)和 Sm~(3+)—Sm~(3+)离子间的能量传移与猝灭。给出了 GdPP 晶体中 Sm~(3+)离子的能级图。

3-5岁幼儿认知灵活性的发展

To test preschoolers’ development of cognitive flexibility--an ability to solve a problem in one way and to then switch solution strategies, and the mechanism involved in the development, 3-5-year-olds are asked to perform switching tasks in which the experimenter manipulates the way the stimuli are presented: consecutive or simultaneous; the way the switching happens: between dimensions or within a dimension; the conceptual domains involved: shape, color, number and direction; the specific labels used. The main results of this work are presented below: (1) 3-5-year-olds’ cognitive flexibility develops with age, yet its development is not of the same speed in extra-dimensional switch tasks and inter-dimensional reversal tasks. 3-year-olds manifest some cognitive flexibility, but their performance is significantly worse than that of 4- and 5-year-olds. For the 3-year-olds, in reversal tasks, although 80% of the children passed the post-switch phrase in color task; less then 60% children passed the post-switch phrase in shape, number and direction tasks. In extra-dimensional tasks, 3-year-olds performance is worse than that in the reversal tasks. Less than 50% of the children passed the tasks. Children’s cognitive flexibility develops fast from 3-year-olds to 4-year-olds. Both 4-year-olds and 5-year-olds demonstrate high flexibility without significant difference between them. (2) Children’s flexibility in the conceptual domains of shape, color, number and direction follows different developing patterns. In inter-dimensional reversal tasks, 3-year-olds’ performance is not the same in the 4 conceptual domains, but the difference among the domains is insignificant in 4-and-5-year-olds. In extra-dimensional switching tasks, children’s performance on the 4 domain tasks is significantly different from one another in 3-, 4-, and 5-year-olds. (3) The way the stimuli are presented affects children’s development of cognitive flexibility. In inter-dimensional reversal tasks, 3-year-olds’ performance in consecutive presentation is significantly better than that in simultaneous presentation. 4- and 5-year-olds’ performance in the 2 presentations is not significantly different from each other. In extra-dimensional switch tasks, 3-, 4-, and 5-year-olds’ performance in the consecutive presentation is not significantly better than that in the simultaneous presentation (4) 3-, 4-, and 5-year-olds’ self-issued labeling aids their performance on the switching tasks. Children’ performance in the labeling condition is significantly better than that of no labeling. (5) 3-5-year-olds’ cognitive flexibility is highly correlated with their working memory and inhibition. Children’ development of cognitive flexibility is a process that involves activation of working memory and inhibition, in which the complexity of the task also plays a role.

4-6岁儿童对情绪表达规则的认知发展研究

情绪表达规则是指一个人应当在恰当的情境中表达恰当的情绪。对情绪表达规则的认知发展是个体社会能力发展的一个重要方面，因此这一主题引起了国内外众多研究者的重视。但目前对童年早期儿童的研究中，大多数只考查了儿童对情绪的外显表达与内隐真实体验的区分，没有同时考查儿童对需要使用情绪表达规则的情境的认知，不能全面真实地揭示儿童对情绪表达规则的认知发展。在本研究中，以个别访谈法考查了4－6岁儿童同一个体在这两个指标上对情绪表达规则认知的发展，以及发展中的个别差异和个体内部差异，并进一步了解情境因素以及心理理论能力、执行抑制能力的发展对它们的影响。主要结果如下： （1）4－6岁儿童对情绪表达规则的认知能力随年龄增长而提高：4岁尚处于发展的萌芽水平，5岁和6岁都处于发展的过渡水平。对于同一年龄的儿童，对情绪表达规则的认知发展存在较大的个体之间的差异。 （2）4－6岁儿童对情绪表达规则的认知也存在较大的个体内部差异：对表情伪装的认知滞后于对需要使用情绪表达规则的情境的认知，对言语伪装的认知优于对表情伪装的认知；在对情绪表达规则的使用中，自我定向的占多数，其次是他人定向，规则定向所占的比例最少。随年龄的增长，自我定向的比例减少，他人定向的比例增多。 （3）情境变量影响4－6岁儿童对情绪表达规则的认知：与同伴交往情境中对需要使用情绪表达规则的情境的认知、对言语伪装的认知优于与长辈交往情境中的有关认知；对需要掩藏消极情绪情境中对表情伪装的认知要优于对需要掩藏积极情绪情境中表情伪装的认知。 （4）4－6岁儿童心理理论能力的发展和执行抑制能力的发展与其对情绪表达规则的认知发展有关。 （5）有关情绪表达规则的提示能够促进儿童对情绪隐私的认知，促进的效果随年龄的增长而提高，6岁的效果最好。

On the contribution of stereochemistry to human ITPK1 specificity: Ins(1,4,5,6)P4 is not a physiologic substrate

Ins(1,4,5,6)P4, a biologically active cell constituent, was recently advocated as a substrate of human Ins(3,4,5,6)P4 1-kinase (hITPK1), because stereochemical factors were believed relatively unimportant to specificity [Miller, G.J. Wilson, M.P. Majerus, P.W. and Hurley, J.H. (2005) Specificity determinants in inositol polyphosphate synthesis: crystal structure of inositol 1,3,4-triphosphate 5/6-kinase. Mol. Cell. 18, 201-212]. Contrarily, we provide three examples of hITPK1 stereospecificity. hITPK1 phosphorylates only the 1-hydroxyl of both Ins(3,5,6)P3 and the meso-compound, Ins(4,5,6)P3. Moreover, hITPK1 has >13,000-fold preference for Ins(3,4,5,6)P4 over its enantiomer, Ins(1,4,5,6)P4. The biological significance of hITPK1 being stereospecific, and not physiologically phosphorylating Ins(1,4,5,6)P4, is reinforced by our demonstrating that Ins(1,4,5,6)P4 is phosphorylated (K(m) = 0.18 microM) by inositolphosphate-multikinase.

Editorial 3

En el momento actual hay abierto un amplio debate sobre la reforma de las enseñanzas primaria y secundaria. Creo que es hora de resaltar el capital humano existente y del que pueden disponer las distintas administraciones educativas en una situación de tal trascendencia.

Isoform-specific inhibition of TRPC4 channel by phosphatidylinositol 4,5-bisphosphate.

Full-length transient receptor potential (TRP) cation channel TRPC4alpha and shorter TRPC4beta lacking 84 amino acids in the cytosolic C terminus are expressed in smooth muscle and endothelial cells where they regulate membrane potential and Ca(2+) influx. In common with other "classical" TRPCs, TRPC4 is activated by G(q)/phospholipase C-coupled receptors, but the underlying mechanism remains elusive. Little is also known about any isoform-specific channel regulation. Here we show that TRPC4alpha but not TRPC4beta was strongly inhibited by intracellularly applied phosphatidylinositol 4,5-bisphosphate (PIP(2)). In contrast, several other phosphoinositides (PI), including PI(3,4)P(2), PI(3,5)P(2), and PI(3,4,5)P(3), had no effect or even potentiated TRPC4alpha indicating that PIP(2) inhibits TRPC4alpha in a highly selective manner. We show that PIP(2) binds to the C terminus of TRPC4alpha but not that of TRPC4beta in vitro. Its inhibitory action was dependent on the association of TRPC4alpha with actin cytoskeleton as it was prevented by cytochalasin D treatment or by the deletion of the C-terminal PDZ-binding motif (Thr-Thr-Arg-Leu) that links TRPC4 to F-actin through the sodium-hydrogen exchanger regulatory factor and ezrin. PIP(2) breakdown appears to be a required step in TRPC4alpha channel activation as PIP(2) depletion alone was insufficient for channel opening, which additionally required Ca(2+) and pertussis toxin-sensitive G(i/o) proteins. Thus, TRPC4 channels integrate a variety of G-protein-dependent stimuli, including a PIP(2)/cytoskeleton dependence reminiscent of the TRPC4-like muscarinic agonist-activated cation channels in ileal myocytes.

Two mercuric ammoniates: [Hg(NH3)(2)][HgCl3](2) and [Hg(NH3)(4)](ClO4)(2)

[Hg(NH3)(2)][HgCl3](2) (1) is obtained by saturating an equimolar solution of HgCl2 and NH4Cl with Hg(NH2)Cl at 75 degreesC. 1 crystallizes in the orthorhombic space group Pmna with a = 591.9(1) pm, b = 800.3(1) pm, c = 1243.3(4) pm, Z = 2. The structure consists of linear cations [Hg(NH3)(2)](2+) and T-shaped anions [HgCl3](-). The coordination sphere of mercury is

Inactivation of V79 cells by low-energy protons, deuterons and helium-3 ions

Previous work by ourselves and by others has demonstrated that protons with a linear energy transfer (LET) about 30 V mu m(-1) are more effective at killing cells than doubly charged particles of the same LET. In this work we show that by using deuterons, which have about twice the range of protons with the same LET, it is possible to extend measurements of the RBE of singly charged particles to higher LET (up to 50 keV mu m(-1)). We report the design and use of a new arrangement for irradiating V79 mammalian cells. Cell survival. measurements have been made using protons in the energy range 1.0-3.7 MeV, deuterons in the energy range 0.9-3.4 MeV and He-3(2+) ions in the energy range 3.4-6.9 MeV;. This corresponds to volume-averaged LET (within the cell nucleus) between 10 and 28 keV mu m(-1) for protons, 18-50 keV mu m(-1) for deuterons, and 59-106 keV mu m(-1) for helium ions. Our results show no difference in the effectiveness of protons and deuterons matched for LET. However, for LET above about 30 keV mu m(-1) singly charged particles are more effective at inactivating cells than doubly-charged particles of the same LET and that this difference can be understood in terms of the radial dose distribution around the primary ion track.