斑点叉尾鮰鱼皮胶原的提取及其基本特性的研究

采用乙酸—胃蛋白酶降解的方法从斑点叉尾鮰鱼皮中提取胶原,利用正交试验优化提取工艺,并对最优工艺条件下提取的鱼皮胶原的基本特性进行了研究。结果表明：鱼皮胶原的最优提取工艺条件是,乙酸浓度为0.5 mol/L,鱼皮与乙酸固液用量之比为1∶100（每克冷冻干燥鱼皮加100 mL乙酸）,胃蛋白酶的添加量为1104 U/mL,提取时间为54 h,提取温度为4℃,间歇搅拌。对鱼皮胶原进行氨基酸分析、傅立叶红外扫描和紫外扫描,结果表明：所提取的鱼皮胶原具有Ⅰ型胶原所特有的氨基酸组成,并且胶原的三股螺旋结构保持完整。     

Biomaterials and biomedical devices

This review discusses the factors important in the incorporation or integration of biomaterials and devices by tissue. Methods for surface modification and surface-sensitive techniques for analysis are cited. In vitro methods to evaluate the biocompatibility or efficacy of certain biomaterials and devices are presented. Present and future directions in neural prostheses, cardiovascular materials, blood or bone substitutes, controlled drug delivery, orthopedic prostheses, dental materials, artificial organs, plasma- and cytapheresis, and dialysis are discussed.     

The path forward for biofuels and biomaterials

Biomass represents an abundant carbon-neutral renewable resource for the production of bioenergy and biomaterials, and its enhanced use would address several societal needs. Advances in genetics, biotechnology, process chemistry, and engineering are leading to a new manufacturing concept for converting renewable biomass to valuable fuels and products, generally referred to as the biorefinery. The integration of agroenergy crops and biorefinery manufacturing technologies offers the potential for the development of sustainable biopower and biomaterials that will lead to a new manufacturing paradigm.     

Scanning tunneling microscopy of freeze-fracture replicas of biomembranes

The high resolution of the scanning tunneling microscope (STM) makes it a potentially important tool for the study of biomaterials. Biological materials can be imaged with the STM by a procedure in which fluid, nonconductive biomaterials are replaced by rigid and highly conductive freeze-fracture replicas. The three-dimensional contours of the ripple phase of dimyristoylphosphatidylcholine bilayers were imaged with unprecedented resolution with commercial STMs and standard freeze-fracture techniques. Details of the ripple amplitude, asymmetry, and configuration unobtainable by electron microscopy or x-ray diffraction can be observed relatively easily with the STM.     

茶树新梢力学试验机的研制

一种微型生物材料力学试验机已经研制成功，这种试验机不仅能准确测定茶树新梢的材料力学参数，从而为研制新型选择性采茶机以及改进现有采茶机的性能提供了重要条件；而且换用适当的夹持装置，还可用来测定其它植物性材料的多种力学参数。     

两种血液相容性生物无机材料的研究进展

对两种血液相容性无机生物材料的最新研究进展进行了综述.着重介绍了类金刚石薄膜(Diamondlike carbon,DLC)、氧化钛薄膜医用抗凝血材料近年来的研究进展,并对血液相容性研究中存在的问题进行了分析.     

两种血液相容性生物无机材料的研究进展

对两种血液相容性无机生物材料的最新研究进展进行了综述.着重介绍了类金刚石薄膜（Diamondlike carbon,DLC）、氧化钛薄膜医用抗凝血材料近年来的研究进展,并对血液相容性研究中存在的问题进行了分析.     

海藻糖在生物组织器官保护方面的新应用

海藻糖是具有独特生物学功能的二糖,它在生物活性材料的保护保存等方面起着不可估量的作用,是一种非常优良的生物活性保护剂。综述了海藻糖在血液、脂质体、气管、肝、肺、肾、胚胎等器官保护中的应用情况及新的发展动态。     

生物质的生物转化与利用研究进展

生物质的生物转化与利用在生物质能源开发、生物质材料制备和生物活性药物制取等领域已取得了丰厚的研究成果。对非粮生物质资源的生物转化与利用研究、生物质资源生物转化生物材料的过程优化研究,生物质资源生物转化生物药物的酶工程研究等方面进行了综述,并对生物质资源生物转化的方式与途径进行了分析。     

Role of intermolecular forces in defining material properties of protein nanofibrils

Protein molecules have the ability to form a rich variety of natural and artificial structures and materials. We show that amyloid fibrils, ordered supramolecular nanostructures that are self-assembled from a wide range of polypeptide molecules, have rigidities varying over four orders of magnitude, and constitute a class of high-performance biomaterials. We elucidate the molecular origin of fibril material properties and show that the major contribution to their rigidity stems from a generic interbackbone hydrogen-bonding network that is modulated by variable side-chain interactions.     

黄绿蜜环菌培养基优化及人工培养条件研究

以黄绿蜜环菌为生物材料进行人工驯化研究,结果显示,该菌适宜碳源为蔗糖,氮源为蛋白胨,适宜的碳氮比为10∶1,最佳矿质营养元素是硫酸镁,最适pH为6.5,在暗处培养生长最佳。此研究结果为黄绿蜜环菌的人工栽培奠定了基础。     

Molecular architecture and evolution of a modular spider silk protein gene

Spider flagelliform silk is one of the most elastic natural materials known. Extensive sequencing of spider silk genes has shown that the exons and introns of the flagelliform gene underwent intragenic concerted evolution. The intron sequences are more homogenized within a species than are the exons. This pattern can be explained by extreme mutation and recombination pressures on the internally repetitive exons. The iterated sequences within exons encode protein structures that are critical to the function of silks. Therefore, attributes that make silks exceptional biomaterials may also hinder the fixation of optimally adapted protein sequences.     

农作物生物炼制的发展现状与展望

 随着世界经济的不断发展,特别是石油资源濒临枯竭和环境污染日益严重,能源和环境等问题日益突出。生物炼制是环境可持续发展和能源经济转变的重要手段。以生物炼制为核心的生物技术第三次浪潮,将解决人类社会目前面临的资源、能源与环境等诸多重要问题。介绍了农作物生物炼制的概念、分类,阐述了农作物生物炼制的产品主要有生物质化学品,生物质材料,生物质能源以及生物可再生原料的修饰等,并展望了农作物生物炼制的发展前景。     

半纤维素酯化和醚化改性研究进展

近些年,从可再生资源获得新的功能性材料引起了广泛关注。半纤维素通过改性后可替代传统化石材料制备新型功能材料。从酯化和醚化两方面论述半纤维素化学改性的研究现状,并对半纤维素改性应用前景进行展望。半纤维素酰氯酯化赋予半纤维素斥水性能而酸酐酯化赋予亲水性能,羧甲基化、甲基化、季碱化和苄基化在半纤维素醚化方面取得很大进展。新的技术应用将会更大程度提高改性半纤维素取代度,为发掘其鲜为人知的用途提供了新窗口。     

Silk genes support the single origin of orb webs

The orb web is a spectacular evolutionary innovation that enables spiders to catch flying prey. This elegant, geometric structure is woven with silk fibers that are renowned for their superior mechanical properties. We used silk gland expression libraries to address a long-standing controversy concerning the evolution of the orb-web architecture. Contrary to the view that the orb-web design evolved multiple times, we found that the distribution and phylogeny of silk proteins support a single, ancient origin of the orb web at least 136 million years ago. Furthermore, we substantially expanded the repository of silk sequences that can be used for the synthesis of high-performance biomaterials.     

Early Cretaceous spider web with its prey

The orb web is a spectacular evolutionary innovation that enables spiders to catch flying prey. This elegant, geometric structure is woven with silk fibers that are renowned for their superior mechanical properties. We used silk gland expression libraries to address a long-standing controversy concerning the evolution of the orb-web architecture. Contrary to the view that the orb-web design evolved multiple times, we found that the distribution and phylogeny of silk proteins support a single, ancient origin of the orb web at least 136 million years ago. Furthermore, we substantially expanded the repository of silk sequences that can be used for the synthesis of high-performance biomaterials.     

Biomass recalcitrance: engineering plants and enzymes for biofuels production

Lignocellulosic biomass has long been recognized as a potential sustainable source of mixed sugars for fermentation to biofuels and other biomaterials. Several technologies have been developed during the past 80 years that allow this conversion process to occur, and the clear objective now is to make this process cost-competitive in today's markets. Here, we consider the natural resistance of plant cell walls to microbial and enzymatic deconstruction, collectively known as "biomass recalcitrance." It is this property of plants that is largely responsible for the high cost of lignocellulose conversion. To achieve sustainable energy production, it will be necessary to overcome the chemical and structural properties that have evolved in biomass to prevent its disassembly.     

环境友好型生物降解材料聚乳酸的性能研究

聚乳酸(PLA)是一类重要的绿色环保型可降解材料,正受到人们越来越多的关注,近年来被广泛应用。笔者简要论述了生物降解材料聚乳酸的物化性能、力学性能及生物降解性能,综述了聚乳酸的合成方法—乳酸直接缩聚法和丙交酯开环聚合法,分析了国内外的生产现状。最后,对聚乳酸的合成及应用前景进行了展望,并指出可生物降解材料聚乳酸一旦工业化,它在医用及降解塑料方面将会有难以估量的应用前景。     

Photoinduced plasticity in cross-linked polymers

Chemically cross-linked polymers are inherently limited by stresses that are introduced by post-gelation volume changes during polymerization. It is also difficult to change a cross-linked polymer's shape without a corresponding loss of material properties or substantial stress development. We demonstrate a cross-linked polymer that, upon exposure to light, exhibits stress and/or strain relaxation without any concomitant change in material properties. This result is achieved by introducing radicals via photocleavage of residual photoinitiator in the polymer matrix, which then diffuse via addition-fragmentation chain transfer of midchain functional groups. These processes lead to photoinduced plasticity, actuation, and equilibrium shape changes without residual stress. Such polymeric materials are critical to the development of microdevices, biomaterials, and polymeric coatings.     

Adherent bacterial colonization in the pathogenesis of osteomyelitis

Direct scanning electron microscopy of material obtained during surgical debridement of osteomyelitic bone showed that the infecting bacteria grew in coherent microcolonies in an adherent biofilm so extensive it often obscured the infected bone surfaces. Transmission electron microscopy showed this biofilm to have a fibrous matrix, to contain some host cells, and to contain many bacteria around which matrix fibers were often concentrated. Many bacterial morphotypes were present in these biofilms, and each bacterium was surrounded by exopolysaccharide polymers, which are known to mediate formation of microcolonies and adhesion of bacteria to surfaces in natural ecosystems and in infections related biomaterials. The adherent mode of growth may reduce the susceptibility of these organisms to host clearance mechanisms and antibiotic therapy and thus may be a fundamental factor in acute and chronic osteomyelitis.