Novel Epoxides of Soloxolone Methyl: An Effect of the Formation of Oxirane Ring and Stereoisomerism on Cytotoxic Profile,Anti-Metastatic and Anti-Inflammatory Activities In Vitro and In Vivo

It is known that epoxide-bearing compounds display pronounced pharmacological activities, and the epoxidation of natural metabolites can be a promising strategy to improve their bioactivity. Here, we report the design, synthesis and evaluation of biological properties of αO-SM and βO-SM, novel epoxides of soloxolone methyl (SM), a cyanoenone-bearing derivative of 18βH-glycyrrhetinic acid. We demonstrated that the replacement of a double-bound within the cyanoenone pharmacophore group of SM with α- and β-epoxide moieties did not abrogate the high antitumor and anti-inflammatory potentials of the triterpenoid. It was found that novel SM epoxides induced the death of tumor cells at low micromolar concentrations (IC₅₀^(24h) = 0.7–4.1 µM) via the induction of mitochondrial-mediated apoptosis, reinforced intracellular accumulation of doxorubicin in B16 melanoma cells, probably by direct interaction with key drug efflux pumps (P-glycoprotein, MRP1, MXR1), and the suppressed pro-metastatic phenotype of B16 cells, effectively inhibiting their metastasis in a murine model. Moreover, αO-SM and βO-SM hampered macrophage functionality in vitro (motility, NO production) and significantly suppressed carrageenan-induced peritonitis in vivo. Furthermore, the effect of the stereoisomerism of SM epoxides on the mentioned bioactivities and toxic profiles of these compounds in vivo were evaluated. Considering the comparable antitumor and anti-inflammatory effects of SM epoxides with SM and reference drugs (dacarbazine, dexamethasone), αO-SM and βO-SM can be considered novel promising antitumor and anti-inflammatory drug candidates.     

Memory complaints and abilities among depressed older adults.

The relation between complaints of memory problems and memory test performance was examined among depressed (n?=?25) and nondepressed (n?=?25) adults over the age of 40 years. Depressed adults were diagnosed from interviews using Diagnostic and Statistical Manual of Mental Disorders (DSM-III) criteria and from responses to the Beck Depression Inventory. A dissociation between memory complaints and performance was observed. Depressed adults complained of greater problems in memory than nondepressed adults. However, the memory test performances of both groups were in the average-to-above-average range. These results are discussed in light of the role of self-deprecating cognitive distortions in the tendency of depressed individuals to negatively evaluate all their abilities, including their memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于电流畸变特性的整流器开路故障诊断系统设计与实现

半导体开关是影响电压源整流器VSR（voltage source rectifier）系统整体故障率的重要因素。为此,提出一种基于电流畸变特性的三相开路故障诊断系统,该系统由诊断模块、寄存器模块和决策模块组成。诊断模块使用滞环比较器来判断电流的变化趋势,从而诊断开路OC（open-circuit）故障;寄存器模块用于实现多开关OC故障诊断;决策模块用于输出最终结果。实验结果表明,该方法能够正确实现包括6种单开关故障和15种不同的双开关故障在内的故障诊断,故障诊断准确性好。此外,所提方法在负载突变、不同功率因数、电网电压不平衡和畸变以及不同的交流滤波器结构条件下均具有良好的抗干扰性能和较强的鲁棒性,平均诊断时间仅为3.68 ms。     

Are financial incentives related to performance? A meta-analytic review of empirical research.

The relationship of financial incentives to performance quality and quantity is cumulated over 39 studies containing 47 relationships. Financial incentives were not related to performance quality but had a corrected correlation of .34 with performance quantity. Setting (laboratory, field, experimental simulation) and theoretical framework moderated the relationship, but task type did not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Empirical and Conceptual Problems With Longitudinal Trait-State Models: Introducing a Trait-State-Occasion Model.

The latent trait-state-error model (TSE) and the latent state-trait model with autoregression (LST-AR) represent creative structural equation methods for examining the longitudinal structure of psychological constructs. Application of these models has been somewhat limited by empirical or conceptual problems. In the present study, Monte Carlo analysis revealed that TSE models tend to generate improper solutions when N is too small, when waves are too few, and when occasion factor stability is either too large or too small. Mathematical analysis of the LST-AR model revealed its limitation to constructs that become more highly auto-correlated over time. The trait-state-occasion model has fewer empirical problems than does the TSE model and is more broadly applicable than is the LST-AR model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oxidative stability of structured lipids produced from sunflower oil and caprylic acid

Traditional sunflower oil (SO), randomized lipid (RL) and specific structured lipid (SL), both produced from SO and tricaprylin/caprylic acid, respectively, were stored for up to 12 wk to compare their oxidative stabilities by chemical and sensory analyses. Furthermore, the effect of adding a commercial antioxidant blend Grindox 117 (propyl gallate/ citric acid/ascorbyl palmitate) or gallic acid to the SL was investigated. The lipid type affected the oxidative stability: SL was less stable than SO and RL. The reduced stability was most likely caused by both the structure of the lipid and differences in production/ purification, which caused lower tocopherol content and higher initial levels of primary and secondary oxidation products in SL compared with RL and SO. Grindox 117 and gallic acid did not exert a distinct antioxidative effect in the SL oil samples during storage.     

‘The crystal structure problem’ in noble gas nanoclusters

Calculations of the energetics of multiply twinned particles (MTPs) such as icosahedra and decahedra with fivefold symmetry as well as face-centered cubic (fcc) and hexagonal close-packed (hcp) particles in the size interval from 13 up to ∼ 45,000 atoms were made applying Lennard-Jones potentials. We essentially extended the size interval comparatively with previous studies and included shape-optimized hcp clusters in the global energy analysis that gives rise to the new insight into the basic fcc/hcp problem. For the cluster size N from minimal up to N ∼ 2000 atoms the binding energy is highest for icosahedra, in the size interval from 2000 up to ∼ 11,500 atoms decahedra prevail, above N ∼ 11,500 atoms decahedra and optimized fcc clusters were found to alternate. The hcp structure was revealed to become favorable above N ∼ 34,000 atoms. Thus, hcp clusters can attain their preference with respect to MTPs (comprising fcc fragments) and optimized fcc clusters only for very large sizes. The comparison with several other models is suggested and the opportunity of experimental observations is discussed.     

微型固体火箭发动机内弹道的数值模拟

随着计算流体力学(CFD)的不断发展, 利用计算机对火箭发动机燃烧室内的气体流动过程进行数值模拟已经成为固体火箭发动机设计中非常重要的一种研究手段, 越来越受到研究人员的重视.文中使用通用流体软件对微型火箭发动机进行内弹道特性的数值模拟进行了研究, 并通过与理论计算所得数值的比较,证明了模拟结果的正确性.     

Social comparison between young children in achievement situations.

Examined the development of children's motivations to socially compare in a situation in which they were free to seek or not seek information about how another child was doing. 16 males and 16 females each at the kindergarten, 1st, and 2nd grade levels were recruited through the newspaper and paid to participate. Pairs of Ss in the same grade worked on a speed task under high- and low-competition conditions. The frequency and duration with which Ss pushed a button to observe their partner's progress on a monitor was the index of the strength of motivation. Results show the expected developmental increase in comparison behavior. Only in 2nd graders did the expected positive relationship between level of competition and performance appear. At the kindergarten level, the means were in the opposite direction, while for the 1st-grade level the relation between competition and performance depended on sex. Results are discussed in terms of alternative predictions derived from theories by L. Festinger (1954) and J. Veroff (1969). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A prescriptive approach for counselor training.

Measured the effectiveness of A. P. Goldstein's (1973) Structured Learning Training (SLT) for teaching confrontation skills to 56 trainees varying in conceptual development (Paragraph Completion Test). Both a self-instruction approach and a standard implementation of SLT were effective for teaching confrontation skills. When trainees' conceptual level (CL) was considered, the approaches proved differentially effective (as measured by pencil-and-paper tests). Self-instruction SLT was more effective with high CL trainees than with low CL trainees; guided-instruction SLT proved more effective than self-instruction SLT with low CL trainees in each treatment. Further, differences due to instructional approach and CL failed to reach significance when the dependent variable was assessed via taped role play. Findings suggest the need for multiple ways of assessing skills as well as multiple approaches for instruction. Further investigation seems necessary to specify the variables involved in maximizing the effect of instruction. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)