新的生物反应器-转基因植物

对新的生物反应器－－转基因植物的研究进展作了综述。与微生物和发酵系统相比较，转基因植物是具有巨大潜力的生物反应器，可以以生产经修饰的生物大分子碳水化合物，脂类，蛋白质，药物等，随着生物技术的发展，将有方法用来提高转基因植物外源基因的表达量。     

中科院等离子体物理所用离子束介导法培育出转基因水稻

中科院等离子体物理所用离子束介导法培育出转基因水稻中科院等离子体物理研究所用离子束介导的方法，将潮霉素抗性基因整合进入水稻ＤＮＡ中，成功地培育出抗潮霉素的转基因水稻。用离子束介导法培育转基因水稻这在国际上属首次。这项研究成果为水稻等农作物的定向育种及...     

转基因玉米MZIR098定量PCR检测方法的建立

利用转基因抗虫耐除草剂玉米MZIR098的5’端旁侧序列信息，设计引物及探针，随后通过qPCR和3D-dPCR平台，建立了玉米MZIR098的转化体特异性双重定量检测方法。经测试后显示，qPCR和3D-dPCR两种检测方法的重复性(相对标准差)均小于25%,符合转基因检测方法相关标准，并且检出限和定量限也无显著差异。上述结果说明2种方法均可满足转基因定量检测的基本需求，可为今后准确高效地检测玉米MZIR098及其产品提供新的参考方法。     

标准物质在转基因产品检测中的应用

<正>伴随着转基因作物种植面积的激增,关于转基因作物及其产品成分对人类健康和生态环境影响的关注度也与日俱增。由于转基因产品长期安全与否尚无定论,广大人民群众对转基因产品的生产和使用存在顾虑。转基因产品检测方法是转基因安全管理的关键因素之一,因此近年来转基因检测方法得到了快速发展和广泛应用。转基因产品的检测方法主要基于外源     

“转基因”再掀安全之争

随着转基因技术的发展和转基因农作物的推广，转基因农产品逐渐深入人们的生活。但人们对待转基因食品的态度却泾渭分明，科学界各方观点分歧严重：相互矛盾的实验证据，极端对立的利益表达，莫衷一是的研究结论，让只是关心转基因食品是否安全的消费者无所适从。一项新技术的发明和推广，都有一个从质疑，认识到接受的过程，转基因食品也不例外，那么转基因食品因何让各界产生如此大的分歧，其背后的原因，值得我们深思。     

基因工程树的现状、生态风险与对策

应用基因工程技术改良树种，具有巨大的经济潜力和社会效益，林业生物工程将可能是继农业生物工程之后又一个热潮，目前，无论是阔叶树种还是针叶树种的转基因都已获得成功，已有几十种转基因树在北美、欧亚大陆，澳洲和非洲释放到野外进行田间试验，尽管当前转基因树木尚未大面积推广种植，人们却已对其生态安全性展开了广泛的争论，这是因为转基因树木可能是迄今所有转基因生物中最具生态风险的种类，其主要的生态风险表现在对周围环境中野生树种可能造成基因污染以及转基因树种作为一类新的外来种入侵，威胁现今已十分脆弱的地球森林生态系统，一些研究转基因树木的主要国家和实验室已开始注意到应从基因水平上采取防范对策，趋利避害，以防止或减少转基因树木对自然环境造成不可逆转的污染和破坏。     

利用转基因植物生产新型疫苗

综述了国内外利用转基因植物生产疫苗研究的现状及进展，从原理、方法、优缺点及发展方向等方面进行了概括。认为从目前来讲，由于发展中国家缺少生产疫苗的系统和保证疫苗活性的冷冻设施，使疫苗的普及和推广受取限制。鉴于转基因植物生产廉价疫苗的优势及其产生的抗原蛋白良好的免疫应答反应，过去依靠微生物或细胞培养系统生产疫苗的方式已不适于疫苗的发展及推广普及，而利用转基因植物生产疫苗可能成为当今疫苗生产的趋势。     

转基因生物安全之食品安全

近年来，转基因食品安全问题越来越受到广泛关注。本文概述了国内外转基因食品的研究发展概况，提出了关于转基因食品安全的有关争议，并针对如何看待转基因食品进行了探讨。     

是否接受转基因食品由消费者选择

“转基因食品“对于人们来说，可能已不再是陌生的词语，但现实中能真正了解转基因食品的人却并非多数。而一直以来，转基因食品的安全性又是一个存在争议的问题，面对转基因食品，人们该何去何从呢?     

转基因食品的检测方法

随着转基因技术的快速发展,转基因作物的种类在不断增加,对转基因食品的定性、定量检测方法也在逐步完善.目前采用的转基因成分检测方法包括核酸检测和蛋白质检测,前者主要有定性PCR、定量PCR、印迹法和基因芯片技术.后者主要有ELISA和Western杂交.文章就这些检测方法进行综述,同时对其面临的问题及未来发展方向进行初步探讨和展望.     

肌肉介导心钠素基因对L-NNA高血压大鼠的作用

用重组人心钠素基因真核表达质粒ｐｃＤＮＡ３／ＡＮＦ，通过基因缝线转移至Ｌ－ＮＮＡ高血压大鼠股四头肌，发现可明显降低Ｌ－ＮＮＡ引起的高血压，并产生明显的利钠利尿作用。提示肌肉介导心钠素基因，作为一种ＤＮＡ药物治疗高血压，可能具有潜在应用价值。     

Deforming-Spatial-Domain/Stabilized Space–Time (DSD/SST) method in computation of non-Newtonian fluid flow and heat transfer with moving boundaries

This work presents an extension of the Deforming-Spatial-Domain/Stabilized Space–Time (DSD/SST) method to non-Newtonian fluid flow and heat transfer with moving boundaries. In this method, the variational formulation is written over the space–time domain. Three sets of stabilization parameters are used for the continuity, momentum and thermal energy equations. The more efficient solution for highly non-linear problems is achieved by using the Newton–Raphson iterative method for non-linear terms and the generalized minimal residual method for algebraic equations. This work makes the computations feasible with third-order accuracy in time, which is higher then most versions of the FEM. To validate this method, it is used to solve the well-known benchmark problems such as channel-confined flow, lid-driven cavity, flow around a cylinder, and flow in channel with wavy wall, where the non-Newtonian fluid rheological behaviour is incorporated. In particular, the results in terms of the Nusselt number, wall shear stress (WSS), vorticity fields and streamlines are discussed. It shows that the flow and heat transfer characteristics are quite different if the moving boundaries are taken into account. In summary, this work provides an effective extension of the DSD/SST method to hydrodynamics and heat transfer problems involving complex fluids and moving boundaries.     

需求驱动型供应链物流仿生优化设计框架

为提高供应链运作效率,运用仿生学理论和方法,仿生生物基因表达调控模式对需求驱动型供应链物流进行了优化设计。分析了基因表达调控机制,建立了基因表达调控的“功能-行为-结构”模式,识别了需求驱动型供应链物流与基因表达调控过程的相似性,提出了包括需求驱动--响应机制、设施位置、信息传输过程和物流路径在内的需求驱动型供应链物流仿生设计框架。研究表明,仿生设计能够从整体上优化供应链物流的运作过程,提高运作效率。     

Fabrication of DNA-antibody–apatite composite layers for cell-targeted gene transfer

Surface-mediated gene transfer systems using apatite (Ap)-based composite layers have received increased attention in tissue engineering applications owing to their safety, biocompatibility and relatively high efficiency. In this study, DNA-antibody–apatite composite layers (DA–Ap layers), in which DNA and antibody molecules are immobilized within a matrix of apatite nanocrystals, were fabricated using a biomimetic coating process. They were then assayed for their gene transfer capability for application in a specific cell-targeted gene transfer. A DA–Ap layer that was fabricated with an anti-CD49f antibody showed a higher gene transfer capability to the CD49f-positive CHO-K1 cells than a DNA–apatite composite layer (D–Ap layer). The antibody facilitated the gene transfer capability of the DA–Ap layer only to the specific cells that were expressing corresponding antigens. When the DA–Ap layer was fabricated with an anti-N-cadherin antibody, a higher gene transfer capability compared with the D–Ap layer was found in the N-cadherin-positive P19CL6 cells, but not in the N-cadherin-negative UV♀2 cells or in the P19CL6 cells that were pre-blocked with anti-N-cadherin. Therefore, the antigen–antibody binding that takes place at the cell–layer interface should be responsible for the higher gene transfer capability of the DA–Ap than D–Ap layer. These results suggest that the DA–Ap layer works as a mediator in a specific cell-targeted gene transfer system.     

Fabrication of DNA-antibody–apatite composite layers for cell-targeted gene transfer

Abstract

Surface-mediated gene transfer systems using apatite (Ap)-based composite layers have received increased attention in tissue engineering applications owing to their safety, biocompatibility and relatively high efficiency. In this study, DNA-antibody–apatite composite layers (DA–Ap layers), in which DNA and antibody molecules are immobilized within a matrix of apatite nanocrystals, were fabricated using a biomimetic coating process. They were then assayed for their gene transfer capability for application in a specific cell-targeted gene transfer. A DA–Ap layer that was fabricated with an anti-CD49f antibody showed a higher gene transfer capability to the CD49f-positive CHO-K1 cells than a DNA–apatite composite layer (D–Ap layer). The antibody facilitated the gene transfer capability of the DA–Ap layer only to the specific cells that were expressing corresponding antigens. When the DA–Ap layer was fabricated with an anti-N-cadherin antibody, a higher gene transfer capability compared with the D–Ap layer was found in the N-cadherin-positive P19CL6 cells, but not in the N-cadherin-negative UV♀2 cells or in the P19CL6 cells that were pre-blocked with anti-N-cadherin. Therefore, the antigen–antibody binding that takes place at the cell–layer interface should be responsible for the higher gene transfer capability of the DA–Ap than D–Ap layer. These results suggest that the DA–Ap layer works as a mediator in a specific cell-targeted gene transfer system.     

Surface-mediated gene transfer from nanocomposites of controlled texture

Safe and efficient gene delivery would have great potential in gene therapy and tissue engineering, but synthetic biomaterial surfaces endowed with efficient gene-transferring functions do not yet exist. Inspired by naturally occurring biomineralization processes, we co-precipitated DNA with inorganic minerals onto cell-culture surfaces. The DNA/mineral nanocomposite surfaces obtained not only supported cell growth but also provided high concentrations of DNA in the immediate microenvironment of the cultured cells. Gene transfer from the engineered surfaces was as efficient as an optimized commercial lipid transfection reagent; in addition, the extent of gene transfer was adjustable by varying the mineral composition. DNA/mineral nanocomposite surfaces represent a promising system for enhancing gene transfer and controlling the extent of gene transfer for various biomedical applications, including tissue engineering or gene therapy of bone.     

受控线性多体系统传递矩阵法

受控线性多体系统的稳态运动是多体系统动力学的重要研究内容之一。本文以简单的受控多体系统为例，建立了受控线性多体系统传递矩阵法，能方便快捷地求解受控线性多体系统的稳态运动。建立了控制力作用下集中质量和弹簧阻尼铰的扩展传递矩阵和扩展传递方程。将牛顿法和受控线性多体系统传递矩阵法的计算结果进行了比较。实例表明，受控线性多体系统传递矩阵法不仅能用于受控线性多体系统的动力学分析，而且完整地保持了传递矩阵法的所有优点。     

Non-viral gene delivery regulated by stiffness of cell adhesion substrates

Non-viral gene vectors are commonly used for gene therapy owing to safety concerns with viral vectors. However, non-viral vectors are plagued by low levels of gene transfection and cellular expression. Current efforts to improve the efficiency of non-viral gene delivery are focused on manipulations of the delivery vector, whereas the influence of the cellular environment in DNA uptake is often ignored. The mechanical properties (for example, rigidity) of the substrate to which a cell adheres have been found to mediate many aspects of cell function including proliferation, migration and differentiation, and this suggests that the mechanics of the adhesion substrate may regulate a cell's ability to uptake exogeneous signalling molecules. In this report, we present a critical role for the rigidity of the cell adhesion substrate on the level of gene transfer and expression. The mechanism relates to material control over cell proliferation, and was investigated using a fluorescent resonance energy transfer (FRET) technique. This study provides a new material-based control point for non-viral gene therapy.     

Fabrication of a DNA-lipid-apatite composite layer for efficient and area-specific gene transfer

A surface-mediated gene transfer system using biocompatible apatite-based composite layers has great potential for tissue engineering. Among the apatite-based composite layers developed to date, we focused on a DNA-lipid-apatite composite layer (DLp-Ap layer), which has the advantage of relatively high efficiency as a non-viral system. In this study, various lipid transfection reagents, including a newly developed reagent, polyamidoamine dendron-bearing lipid (PD), were employed to prepare the DLp-Ap layer, and the preparation condition was optimized in terms of efficiency of gene transfer to epithelial-like CHO-K1 cells in the presence of serum. The optimized DLp-Ap layer derived from PD had the highest gene transfer efficiency among all the apatite-based composite layers prepared in this study. In addition, the optimized DLp-Ap layer demonstrated higher gene transfer efficiency in the presence of serum than the conventional particle-mediated systems using commercially available lipid transfection reagents. It was also shown that the optimized DLp-Ap layer mediated the area-specific gene transfer on its surface, i.e., DNA was preferentially transferred to the cells adhering to the surface of the layer. The present gene transfer system using the PD-derived DLp-Ap layer, with the advantages of high efficiency in the presence of serum and area-specificity, would be useful in tissue engineering.     

借助聚合物实现石墨烯转移的技术进展

高质量、低成本、绿色制备石墨烯及其高效转移技术是促进石墨烯应用和行业发展的关键。目前制备大面积高质量石墨烯的主流方法是基于金属表面催化生长的化学气相沉积法。薄膜转移技术作为连接石墨烯制备和应用的重要桥梁,在实现石墨烯产业化应用中发挥着重要作用。当前石墨烯薄膜的转移技术主要是利用各种聚合物作衬底或支撑材料的直接和间接转移技术。分类介绍了借助单一聚合物转移、复合结构聚合物转移和其他聚合物转移等石墨烯薄膜的转移方法,并对各自的特点进行了分析和总结,比较了各自的优劣势,给出了对应的适用场合。最后展望了石墨烯转移技术的发展方向。