A Novel Dimeric Eremophilane from Ligularia virgaurea spp. oligocephala

A novel dimeric eremophilane, ligulolide B, was isolated from the alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala. The structure was elucidated by various spectroscopic methods including intensive 2D NMR techniques （^1H-^1H COSY, gHMQC, gHMBC and ^1H-^1H NOESY） and HR-ESI-MS.     

Amperometric monitoring of lactate accumulation in rabbit ischemic myocardium

Fabrication and characterization of miniature, flexible, planar biosensors for monitoring l-lactate accumulation in an ischemic myocardium are described. Three configurations of Au-based electrodes were fabricated by a photolithographic technique on flexible polyimide Kapton((R)) foil. All sensors are based on an immobilized lactate oxidase with amperometric detection of the enzymatically produced hydrogen peroxide at a platinum-electroplated-gold base electrode polarized at 0.5 V versus Ag/AgCl. An inner electropolymeric layer is used to prevent electrode fouling and to reject the interference effects of easily oxidizable molecules. In addition, a diffusion controlling outer layer that greatly enhances the linear dynamic range of the sensor, is obtained by casting a polyurethane external film. The developed sensor was evaluated in vitro and proved to have high selectivity, good operational stability, good accuracy and precision (average recovery = 102.3 +/- 0.4% for control sera), fast response time (t(95) = 20 s) and high upper limit of the linear dynamic range (25-80 mM, with sensitivity of 1.7-0.4 nA mM(-1) respectively at PO(2) = 15 mmHg). Subsequently, the sensor was brought into direct contact with the surface of the rabbit papillary muscle and used for continuous quantitative monitoring of extracellular lactate accumulation during no-flow ischemia.     

一类齐次对称多项式上的切比雪夫不等式

本文借助于控制不等式及数学归纳法，将著名的切比雪夫不等式推广到m次一般齐次对称多项式上(如文中定理及引理7)，并将此结果用于对称平均等．旨在展示证明解析不等式的一些有效的方法和技巧，同时为数学研究特别是高维几何研究提供一些新的有趣而有用的解析不等式．     

Evolution of star clusters with a mass distribution of binaries

Summary The dynamical evolution of star clusters with a initial population of binaries strongly depends on the parameters of the bounded pairs. We performed computational simulation with directN-body codes, on models withN=300 objects, with initial fraction of 20% of binaries with the same orbital semi-axis and with a Salpeter mass spectrum. The results are compared with previous analysis on similar equal-mass star models. The calculation points out that binaries with different mass companions determine an enhanced and sudden expansion of the system with neither core collapse nor central mass segregation. Paper presented at the 2° Convegno Nazionale di Fisica Cosmica, held at L'Aquila, 29 May – 2 June 1984.     

Computational prediction of ion permeation characteristics in the glycine receptor modified by photo-sensitive compounds

We conduct computational analyses of ion permeation characteristics in a model glycine receptor (GlyR) modified by photo-sensitive compounds. In particular, we consider hypothetical attachment to the channel of charge-neutral chemical groups which can be photo-activated by shining light of an appropriate wavelength on the system. After illumination, the attached molecules become charged via a photodissociation process or excited into a charge-separated state (thus generating a significant electric dipole). We carry out Brownian Dynamics simulations of ion flow through the channel in the presence of the additional charges generated in this fashion. Based on these calculations, we predict that photo-activation of appropriately positioned photo-sensitive compounds near the channel mouth can significantly modify the rate of ion permeation and the current rectification ratio. Possible implications for GlyR-based device designs are briefly discussed.     

PCB-126 effects on aryl hydrocarbon receptor,ubiquitin and p53 expression levels in a fish product (Sparus aurata L.)

The aim of the present study is to determine if Ahr ligands as PCB-126, a dioxin-like, might contribute to inhibition of the tumour suppressor p53 by promoting its degradation through proteasome-ubiquitin system (UPS). The findings show, in the presence of PCB-126, a significant increase in p53 immunoreactivity in fish compared to the control. Subsequently, there is a decrease in p53 immunoreactivity at 24 h which is maintained even at 72 h. There is also a slight decrease in ubiquitin immunoreactivity to 12 h compared to the control and a marked decrease to 24 and 72 h. It’s very important to underline as in this study we demonstrate a marked decrease in ubiquitin and p53 immunoreactivity at 24 and 72 h. Our result emphasise the need to deeply the role of this receptor in UPS regulation as potential therapeutic target for cancer treatment.     

用ZEMAX软件辅助迈克耳孙干涉仪实验教学

利用ZEMAX软件设计了迈克耳孙干涉仪实验光路.软件绘制的不同显示方式的实验光路外形图,使学生对实验光路建立起了清晰的图像.通过编写ZPL程序实现了对实验现象的动态模拟,使学生对理想情况下的实验现象有一个准确的把握.通过在软件中改变光路主要参数分析了不同方面和不同程度的误差对干涉条纹的影响,其结论对学生在实验中进行有效而准确的调节起到了指导作用.     

Histomorphometric analysis of glucocorticoid-induced osteoporosis

Bone histomorphometry or quantitative histology consists of counting or measuring tissue components: cells, extracellular constituents and microarchitecture. Bone histomorphometry is the only method that allows the measurement of mineralization rate and the study of bone formation at three levels: cell, remodeling unit and tissue levels. It is a useful tool to explain the pathogenesis and cellular mechanisms of different metabolic bone diseases such as glucocorticoid-induced osteoporosis (GIO).

Glucocorticoids (GC) affect calcium and bone metabolism at every level, but the main effect is the osteoblastic dysfunction.

Concerning the bone formation, some histomorphometric studies have shown a depressed osteoblastic activity at a cell, bone remodeling unit, and tissue levels. In addition, there is evidence of a shortening of the period in which the osteoblasts work actively forming the bone matrix. This latter effect seems to occur after high cumulative doses of GC. With regard to the resorption, the results are still debated, but histomorphometric parameters seem to be increased in the majority of studies, at least in the first period of the GC treatment. From a structural point of view, GC seem to induce a thinning of the trabeculae without their perforation, which occurs only after high cumulative doses. Antiresorptive treatments, such as bisphosphonates, are able to counteract the negative effects of GC on bone. In particular, along with their active working period, they prolong the lifespan of osteoblasts and osteocytes. In addition, the antiresorptive treatments seem to extend the time for secondary mineralization through a reduction of the Activation Frequency. The latter is an intriguing mechanism of bisphosphonates in GIO that needs further ad hoc investigations.     

Noncommutative Differential Calculus Approach to Discrete Symplectic Schemes on Regular Lattice

By means of a noncommutative differential calculus on function space of discrete Abelian groups and that of the regular lattice with equal spacing as well as the discrete symplectic geometry and a kind of classical mechanical systems with separable Hamiltonian of the type H(p, q) = T(p) + V(q) on regular lattice, we introduce the discrete symplectic algorithm, i.e., the phase-space discrete counterpart of the symplectic algorithm including original symplectic schemes and the jet-symplectic schemes in terms of the discrete time jet bundle formalism, on the regular lattice. We show some numerical calculation examples and compare the results of different schemes.