仿蛇变体机器人运动机理研究

本文设计了一种蛇形机器人，分析了蛇形机器人的结构，详细讨论了蛇形机器人的运 动机理和几何结构关系，并推导出蛇形机器人的控制算法和相应的控制程序，蛇形机器人在 程序控制下能够向前、向后运动，在一定程度上实现了蛇的运动．     

蛇肉及其有限酶解液营养成分的分析

对蛇肉及其有限酶解液营养成分进行了分析.结果表明:蛇肉含有丰富的蛋白质、维生素和矿物元素,而且构成其蛋白质的氨基酸种类齐全,必需氨基酸含量丰富,其营养价值高于牛肉、鸡肉、鱼肉等肉制品;水解度为22.3%的蛇肉有限酶解液含有蛇肉的全部营养素(蛋白质除外)种类,该有限酶解液还含有平均相对分子质量为538的低肽分子近3%,这些低肽分子占酶解液中总氨基酸含量的56.28%,而游离氨基酸只占总氨基酸含量的43.72%.     

造影图像序列中动脉血管的三维测量

针对X射线心血管造影图像的后处理问题,本文提出一种采用两个近似正交的单面X射线造影图像序列对冠状动脉的三维形状和运动参数进行定量测量的方法.该方法首先采用snake技术从两个角度的图像中重建出各时刻的三维血管轴线.根据三维重建和二维提取的结果,完成对血管形状参数(如长度和腔径)的测量.然后将血管运动场的估计转化为对相邻时刻间血管分支轴线的逐点匹配,并获得位移幅值和运动轨迹等重要参数.最后分别采用模型的X射线图像、计算机模拟数据和临床图像对该方法进行了验证.实验结果表明,该方法是可行的.     

龟形蛇纹寿图案的文化基因分析与设计应用研究

目的 天水龟形蛇纹寿是建筑装饰的吉祥图案,蕴含着丰富的地域文化特色,在造型文化等方面凸显着时代印记和审美趋向,但该图案目前并没有完全融入当代生活。应借助现代的、科学的、合理的设计方法,拉近传统与时尚的距离,提升龟形蛇纹寿图案的知名度,从而实现传统优秀地域文化资源的活化再生。方法 首先通过文献资料、书籍资料、实地考察等方法对该图案的文化基因进行分析,包括显性和隐性两部分,从而为后文的设计演化应用提供了强有力的理论支撑;接着,依据理论分析结果从不同的层次出发,绘制CGM设计要素模型,形成造型库,通过用户调研法,提取核心文化因子;然后,构建数字化APP的应用模型和界面设计,以现代传播平台的方式提升受众的参与感和互动性;最后,进行具体的案例实践,形成新图案,并运用到室内装饰设计中,以验证此APP的可行性。结论 将龟形蛇纹寿图案进行设计演化,不仅是形式上的创新,更是基因的流变,使其更符合现代的审美需求,扩大受众圈,促使文化的用途变得更广泛,展示的机会变得更多样。     

一种基于运动场的snake算法

在计算光流场的基础上,提出了snake算法中一种新的外部能量函数,并利用光流场的运动矢量来预测下帧图像中snake的初始值,不仅与无预测的算法相比能提高收敛的速度,而且收敛结果更贴近于目标的本身。实验证明了该文算法的优越性。     

Isolation and biological characterization of a basic phospholipase A₂ from <i>Bothrops jararacussu</i> snake venom

A phospholipase A₂ has been isolated from Bothrops jararacussu venom from snakes that inhabit the northeast region of Argentina. The present study describes in vivo and in vitro biological activities of phospholipase A₂ from B. jararacussu as well as isolation details of its. Venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20–30ºC) rooms. Snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. The enzyme was purified by gel filtration on a Sephadex G-75 column followed by ion exchange chromatography on a SP-Sephadex C25 column. The major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of KCl that exhibited phospholipase activity.
This basic PLA₂ consists of a single polypeptide chain with a molecular mass of 15.6 kDa. It had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. The enzyme showed a low lethality (LD₅₀ 148.6 µg) when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma CK activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. Myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of CK level just after 1 hour mice injection. Moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase A₂ . These findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. However, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.     

Differentiation between proteolytic activation and autocatalytic conversion of human prothrombin. Activation of recombinant human prothrombin and recombinant D419N-prothrombin by snake venoms from Echis carinatus and Oxyuranus scutellatus

Recombinant human prothrombin (r-prothrombin) and recombinantmutant prothrombin with active site Asp419 substituted by Asn(D419N-prothrombin) were expressed in recombinant CHO cells,isolated and purified from the fermentation supernatant. Ther-Prothrombin and D419N-prothrombm were digested by both Echiscarinatus venom and Oxyuranus scutellatus venom. Prior to, duringand after activation, generation of thrombin activity and theproteolytic degradation of the prothrombin polypeptide chainwere analysed. Owing to the recombinant preparation and inactivityof D419N-prothrombin and its activation products, the proteolyticaction of E.carinatus and O.scutellatus venoms could be studiedwithout addition of thrombin inhibitor, without interferencefrom autocatalytic digestion of prothrombin and in the absenceof any other blood coagulation protease. The comparison betweenthe activation of r-prothrombin and D419N-prothrombin by snakevenoms permitted differentiation between proteolytic activationand autocatalytic conversion of prothrombin. Incubation of D419N-prothrombinwith E.carinatus venom resulted in the generation of stableD419N-meizothrombin by hydrolysis of the peptide bond Arg320-Ile321.By contrast, O.scutellatus venom exhibited activity towardspeptide bonds Arg320-Ile321 and Arg271-Thr272 and lower activitytowards peptide bond Arg155-Ser156, thus converting D419-prothrombininto D419N-thrombin and also liberating Fragment-1, Fragment-2and Fragment-1/2 activation peptide. Activation of r-prothrombinby E.carintitus and O.scutellatus venoms demonstrated the autocatalyticpotential of prothrombin-derived molecules and indicated thatmeizothrombin hydrolysed the cleavage between Fragment-2 andthrombin A-chain in the meizothrombin molecule, but not in prothrombin,preferentially at position Arg284-Thr285. By contrast, bothmeizothrombin and thrombin exhibited no detectable activitytowards peptide bond Arg320-Ile321 between thrombin A- and B-chain,although this site exhibits the optimum sequence for thrombincleavage.     

在大肠杆菌中表达蝮蛇毒类凝血酶基因gloshedobin

将大连蛇岛蝮蛇毒腺中的类凝血酶基因gloshedobin克隆到pET-32a(+)上,构建了T7启动子控制的大肠杆菌表达质粒,并考察了质粒的稳定性. 采用IPTG诱导,以融合蛋白的形式进行表达,得到以包涵体形式存在的类凝血酶. 通过实验对诱导时间、诱导温度及诱导剂浓度进行了优化,并采用正交实验考察了金属离子对表达的影响,结果表明Fe3＋, Co2＋对类凝血酶的表达有促进作用.     

蛇笼树脂的分离性能

合成了弱酸强碱型蛇笼树脂,以腈纶纺丝溶剂为分离液,研究了温度、进样量、进样浓度、柱高等因素对蛇笼树脂分离性能的影响,进行了树脂连续分离应用试验,找出了较好的使用条件。     

一种自动初始化轮廓的改进蛇模型算法

在Snake模型的初始化中存在不易实现自动化或初始化轮廓远离真实轮廓的问题,针对这些问题,本文提出了一种基于灰度梯度的自动初始化蛇模型方法,在针对一般灰度图像和CT图像的边缘提取取得了较好的效果.