基于人眼光学模型的角膜模型的研究

位于眼球最前端的角膜是人眼光学系统的主要屈光元件之一,建立角膜模型具有重要的研究和临床意义。基于角膜面型的非球面特性,应用光学设计软件Zemax,从光学成像角度,提出了结合人眼光学模型的角膜双二次曲面模型的建立,并结合国人正视眼和近视眼的有关实测数据和分析结果,以人眼的波像差为评价函数,通过对初始模型眼的优化,给出了符合我国人眼特点的正视眼和近视眼模型中的角膜模型,讨论了矫正近视的矫正眼模型中的角膜理想模型和可用于角膜屈光手术中的切削模型。基于人眼光学模型的角膜双二次曲面模型也可为波像差引导的个性化角膜切削方案提供一个更适于实际应用的数字化模型。     

Follow the (Industry) Money – The Impact of Science Networks and Industry-to-University Contracts on Academic Patenting in Nanotechnology and Biotechnology

We investigated the factors influencing an academic's propensity to patent and the quality of patenting in nanotechnology and biotechnology. We found that a university researcher is more likely to be listed as an inventor of a patented innovation, regardless of the assignee, if he receives private funding, has a fairly high level of cliquishness in the scientific network and has shown a prior capacity to successfully collaborate with industry, a concept that we named innovation loops. Furthermore, citation rate and number of claims, which are used to represent patent quality, are influenced by factors similar to those explaining patent quantity.     

The importance of peripheral sequences in determining the metal selectivity of an in vitro-selected Co(2+) -dependent DNAzyme

DNAzymes are catalytically active DNA molecules that use metal cofactors for their enzymatic functions. While a growing number of DNAzymes with diverse functions and metal selectivities have been reported, the relationships between metal ion selectivity, conserved sequences and structures responsible for selectivity remain to be elucidated. To address this issue, we report biochemical assays of a family of previously reported in vitro selected DNAzymes. This family includes the clone 11 DNAzyme, which was isolated by positive and negative selection, and the clone 18 DNAzyme, which was isolated by positive selection alone. The clone 11 DNAzyme has a higher selectivity for Co(2+) over Pb(2+) compared with clone 18. The reasons for this difference are explored here through phylogenetic comparison, mutational analysis and stepwise truncation. A novel DNAzyme truncation method incorporated a nick in the middle of the DNAzyme to allow for truncation close to the nicked site while preserving peripheral sequences at both ends of the DNAzyme. The results demonstrate that peripheral sequences within the substrate binding arms, most notably the stem loop, loop II, are sufficient to restore its selectivity for Co(2+) over Pb(2+) to levels observed in clone 11. A comparison of these sequences' secondary structures and Co(2+) selectivities suggested that metastable structures affect metal ion selectivity. The Co(2+) selectivity of the clone 11 DNAzyme showed that the metal ion binding and selectivities of small, in vitro selected DNAzymes may be more complex than previously appreciated, and that clone 11 may be more similar to larger ribozymes than to other small DNAzymes in its structural complexity and behavior. These factors should be taken into account when metal-ion selectivity is required in rationally designed DNAzymes and DNAzyme-based biosensors.     

Effect of amino acids on red pigments and citrinin production in Monascus ruber

Amino acids were used as sole nitrogen sources to examine their effects on the production of water-soluble red pigments and citrinin by Monascus ruber ATCC 96218 cultivated on chemically defined media. In general, when glycine, tyrosine, arginine, serine, or histidine were used as sole nitrogen sources, they favored the production of red pigments, and restricted the synthesis of the mycotoxin. In contrast, the production of citrinin was enhanced in media supplemented with either glutamate, alanine, or proline. Histidine was found to be the most valuable amino acid as it resulted in the highest production of red pigments and almost completely eliminated the formation of mycotoxin.     

生物工程牛羊肉的质量和安全性研究进展

生物工程动物在畜牧业生产以及生物医学上具有广阔和诱人的应用前景,但是生物工程肉制品的安全性在世界范围内备受关注。综述生物工程技术的应用及生物工程牛羊肉的质量和安全性研究进展,并介绍了生物工程动物的社会化进程。     

半无限大生物组织中光子分布规律的研究

光子在生物组织中的传播和分布问题, 是影响光动力疗法治疗结果的重要因素之一。本文给出了蒙特卡罗方法模拟半无限大均匀生物组织中光子分布的计算方法和模拟结果, 分析了半无限大生物组织中光子分布规律。结果表明, 生物组织的光学性质强烈影响光在组织中的分布情况。具有低散射系数, 低吸收系数和高各项异性因子的生物组织, 有利于光子深入均匀地分布其中。力图为光动力疗法的临床应用提供了有效的诊断和治疗依据。     

基于虚拟仪器的激光光斑自动采集与分析系统

为了得到激光光束的某些参量,为设计和改进激光器提供依据,建立了一套激光光斑自动采集与分析系统,搭建了实验平台,并编写了一套基于虚拟仪器开发平台LabVIEW及其图像处理软件包NI Vision的用于采集和分析激光光斑的软件。该软件能实时显示光斑中心位置的漂移轨迹、在x方向和y方向漂移的标准差及其随时间变化的趋势等,同时,还能对基模高斯光束进行分析。经过去噪处理的光斑图样能以3维灰度图的形式显示出来,得到任意剖面的光强信息,并以此进行高斯曲线拟合,得出拟合参量以判断光强曲线接近高斯曲线的程度。结果表明,这种系统可以动态地采集光斑信息并进行处理,具有实时性。     

微孔板荧光观察一氧化氮影响癌细胞线粒体膜电位

利用微孔板荧光分析仪结合线粒体膜电位特异性荧光探针罗丹明123测量了内外源性一氧化氮对癌细胞线粒体膜电位的影响。实验结果显示添加一氧化氮供体后,荧光强度快速增大,且在较长的一段时间内保持不变,而对照组的荧光强度没有明显变化;此外,加载荧光探针前用一氧化氮合酶抑制剂和一氧化氮供体孵育24 h分别能降低和提高线粒体膜电位。研究结果表明增加内外源性一氧化氮均能提高线粒体膜电位,这对于在细胞器水平认识一氧化氮参与促进癌细胞增殖与转移的过程具有一定的意义。     

制浆造纸废水处理方法原理与研究进展

制浆造纸废水由于其有机物含量高,成分复杂,成为较难处理的工业废水之一,简述了制浆造纸不同工段废水的特点以及造纸废水水质指标,综述了主要的造纸废水处理技术和近年来国内外对制浆造纸废水的研究,为制浆造纸工业废水处理提供一定的借鉴。     

Microfluidic devices for bioapplications

Harnessing the ability to precisely and reproducibly actuate fluids and manipulate bioparticles such as DNA, cells, and molecules at the microscale, microfluidics is a powerful tool that is currently revolutionizing chemical and biological analysis by replicating laboratory bench-top technology on a miniature chip-scale device, thus allowing assays to be carried out at a fraction of the time and cost while affording portability and field-use capability. Emerging from a decade of research and development in microfluidic technology are a wide range of promising laboratory and consumer biotechnological applications from microscale genetic and proteomic analysis kits, cell culture and manipulation platforms, biosensors, and pathogen detection systems to point-of-care diagnostic devices, high-throughput combinatorial drug screening platforms, schemes for targeted drug delivery and advanced therapeutics, and novel biomaterials synthesis for tissue engineering. The developments associated with these technological advances along with their respective applications to date are reviewed from a broad perspective and possible future directions that could arise from the current state of the art are discussed.