Phylogenetic position of sponges in early metazoan evolution and bionic applications of siliceous sponge spicules

Sponges are the oldest and the simplest but not primitive multicellular animals. They represent the earliest evolutionary metazoan phylum still extant. It was a long and painful scientific process to posi-tion the most enigmatic and mysterious metazoan,the Porifera,into their correct phylogenetic place among the eukaryotes in general and multicellular animals in particular. As living fossils,sponges provide the best evidence for the early evolution of Metazoa. More recently,interest has been focused on the bionic applications of sponges' siliceous spicules,after the discovery of their unique structure and high fiber performance. In this review,the emergence of sponges,evolutionary novelties found in sponges,and the phylogenetic position of sponges in early metazoan evolution are highlighted. In ad-dition,the present state of knowledge on silicatein-mediated "biosilica" formation in marine sponges,including the involvement of other molecules in silica metabolism and their potential application in nanobiotechnology and medicine,is given.     

IL-1β regulates the mouse Fas ligand expression in corneal endothelial cells

Constitutively expressed Fas ligand (FasL) in several distinct epithelial cell types appears to protect tissues by inducing apoptosis of Fas immune cells during inflammatory reactions. To study the rela-tionship of FasL and inflammation process in cornea,we examined the effects of inflammatory cytokine IL-1β on the FasL production,expression and cytotoxic function in corneal endothelial cells. In this paper,we demonstrate that IL-1β inhibits the FasL production and expression in corneal endothelial cells. The promoter activities of FasL in these cells are reduced by IL-1β in a dose-dependent manner. Finally,we also find that IL-1β block the cytotoxic effects of FasL derived from corneal endothelial cells to the Fas target cells. These data support the view that FasL derived from corneal endothelial cells modulate inflammation within cornea.     

非义务教育体系实现教育资源效用最大化的探索

市场经济运行机制的建立，使得对市场需求的估算愈加重要。本文针对学校这个相对独立的从事教育职能的经济实体，如何最大限度地提高资源管理水平，优化管理结构进行了初步探讨。     

基于Agent技术的企业业务过程管理系统

以三峡工程的物资供应部门为背景，设计了一个基于MAS的企业业务过程管理系统，系统的核心服务合同，反映了Agent的信念，目标，意图，规划，能力和承诺等思维态度，系统的运行通过服务合同的生命周期过程来实现，较好地解决了传统企业管理信息系统难以适应业务模式变化的问题。     

考虑蒙皮效应的高层结构有限元分析

文章将蒙皮效应引入高层钢结构的计算分析中 ,对结构各组成部分进行有限元分析。在分析过程中将压型钢板等价为正交各向异性平板 ,并对其引入壳体概念。在推导单元刚度矩阵时 ,着重阐述了压型钢板等效剪切模量的形成。最后通过算例 ,将计算结果与参考结果相比较 ,充分验证了蒙皮效应在高层结构中可有效控制建筑物的侧移     

鲁西陆表海高分辨层序地层及海平面变动控制

依据钻孔岩芯和测进资料，对钽西陆表海盆地含煤地层进行了高分辨率层序划分，研究了高分辨率层序地层特点及其控制因素。研究表明，鲁西表海沉积序列中不同级次旋回相互叠加，具有特征的低频（Ⅱ～Ⅲ级）和高频（Ⅳ～Ⅵ级）层序叠加样式；这种相互叠加的旋回结构受控于相互叠置的海平面变化周期，即复合海平面变化。海平面变化周期表现出非对称式突发性上升到缓慢回落的节律性，形成了不对称的旋回记录。     

岳阳市南湖水体富营养化趋势研究

本文监测了湖南岳阳市南湖水体富营养化指标和纳污状况,分析了南湖水体富营养化趋势,探讨了人工水产养殖对南湖水体富营养化的影响.研究结果表明南湖已处于富营养化的边缘.     

高效液相色谱法测定血浆中小蘖硷浓度(英)

研究了心衰病人口服小蘖硷后的吸收性，血浆样品用甲醇预处理以沉淀其蛋白质，小蘖硷测定条件为：μBondapakC18柱（10μm，300×3．9mmi．d．）乙腈和0．02mol／L磷酸混合液（45：55．v／v）为流动相，紫外鉴定器设定在波长为346nm处，进样量为50μl时，最小检测极限为8ng／ml。小蘖硷平均回收率为92．5％，结果表明本试验建立的方法和血浆中黄连素浓度监测有利于指导治疗心衰。     

液相色谱智能化——多段梯度洗脱满意分离条件之启发式自动搜索

本文为高性能液相色谱作定量分析,提供一种新颍方法,自动求得峰形分离良好的色谱图,并由此对于仪表之智能化前景作一展望。利用多段梯度洗脱法来改进分离,会引起搜索该条件之复杂化。为此,启发微机来搜索满意的分离条件,而不去搜索最优分离条件,较为合理而且方便。用本法分析人体血液中21种主要氨基酸组分,获得成功。     

Distributed modeling of the beginning and ending dates and durations of limited temperatures over the rugged terrain of Chongqing

A physically based empirical model was established for the beginning and ending dates (BED) of limited temperatures.Data used were daily mean temperatures from 34 conventional stations in the Chongqing region,measured from 1961 to 2000.Using this model in combination with the distributed modeling results of monthly mean temperatures,we developed a method for creating a distributed simulation of the BED and durations of limited temperatures in the rugged terrain of Chongqing.Spatial distribution maps were generated at a resolution of 100×100 m for the BED and durations of the limited temperatures of 0,10,15 and 20.Simulations suggest that the distributed model is able to successfully reveal the macroscopic trends and local distributions.For the modeled BED,the mean absolute bias error is 0.6-2.4 d.Cross-validation and case-year tests show mean absolute bias errors of 1.3-2.8 d and 0.7-2.5 d,respectively.Comparison shows that the simulation results are consistent with the field investigations.This implies that the simulations are as good as observations,thus providing a viable technique for simulating mountainous heat resources using conventional meteorological data.