转基因受体酵母菌的低能氩离子注入研究

通过不同剂量的低能Ar 注入酿酒酵母Ke-y,筛选出了一种较好的菌体保护液,获得了一系列Ar 注入参数。在该研究体系内,Ar 最佳注入剂量分别为9 0×1015 ions/cm2 或13 5×1015 ions/cm2(适于IBB Device 1 型离子注入机)和1 0×1016ions/cm2 或1 4×1016 ions/cm2(适于LZD1000型离子注入机),为离子束介导外源基因组DNA在酵母菌Ke-y中的遗传转化奠定了基础。     

产β-葡萄糖苷酶菌株的筛选鉴定及其离子束诱变

利用经过改良的初筛培养基,以p-NPG为底物作为筛子,从葡萄园土壤及葡萄表皮中筛选到一株产β-葡萄糖苷酶酶活较高的茵株,经18S rDNA鉴定为黑曲霉.通过离子束注入技术对该茵株进行诱变,获得了一株高产β-葡萄糖苷酶诱变菌株H68,与原茵株相比,酶活提高了53%.     

离子束介导大豆DNA转化小麦后代高蛋白株的RAPD标记分析

利用离子束介导法将大豆DNA导入小麦,经过连续4代田间筛选和蛋白含量测定,获得高蛋白变异株系.采用RAPD分析技术,用34条随机引物对供体大豆、受体小麦和3个高蛋白小麦变异株的基因组DNA进行扩增.有29个引物扩增出清晰稳定的条带,其中18个引物扩增出的条带有不同程度的差异.高蛋白小麦突变株与受体小麦(对照)相比出现了条带的增加、缺失、扩增带深浅等变化,也出现了与受体小麦不同而与供体大豆相同的扩增带.实验结果表明,外源大豆DNA导入受体小麦可以引起后代基因组DNA序列变化,扩大小麦遗传基础.     

氮离子束注入姬松茸担孢子的生物学效应研究

氮离子束注入与紫外线辐射对姬松茸担孢子萌发的影响显著不同,表现出一定程度的马鞍型效应.不同剂量的氮离子束注入姬松茸担孢子,其产生的生物学效应不同:氮离子注入束流为200×2.6×1013N /cm2,筛选到一株箱栽生物学效率提高47.0%的姬松茸新菌株AbML11;氮离子注入束流为400×2.6×1013N /cm2,筛选到一株子实体呈现白色突变的姬松茸新菌株AbML7;氮离子注入束流为500×2.6×10"N13/cm2,筛选到一株具有AEC抗性突变的姬松茸新菌株AbML2.     

N+离子注入对干旱胁迫条件下甘草幼苗的SOD酶和CAT酶活性及丙二醛含量的影响

以低能氮离子束为诱变源,对甘草种进行注入处理后,以萌发的幼苗为材料对其在干旱胁迫条件下保护酶活性及MDA含量变化进行研究.结果表明注入后甘草种的存活率呈现马鞍形曲线变化,其中在4.1×1016N+/cm2剂量处达到鞍点,在剂量4.6×1016N+/cm2处存活率高于对照.在干旱胁迫下,随着胁迫时间的延长,离子束注入后萌发的幼苗MDA含量明显低于对照.酶活结果显示,在干旱胁迫后期,剂量4.6×1016N+/cm2处理后的甘草幼苗SOD和CAT酶活性都高于对照,说明该注入剂量处理甘草种有助于提高甘草幼苗的抗旱性能,SOD同工酶结果也证明该剂量的离子注入对干旱胁迫下同工酶谱带有所影响.     

Verification of Beam Models for Ionic Polymer-Metal Composite Actuator

Ionic Polymer-Metal Composite (IPMC) can work as an actuator by applying a few voltages.A thick IPMC actuator,whereNafion-117 membrane was synthesized with polypyrrole/alumina composite filler,was analyzed to verify the equivalent beamand equivalent bimorph beam models.The blocking force and tip displacement of the IPMC actuator were measured with a DCpower supply and Young’s modulus of the IPMC strip was measured by bending and tensile tests respectively.The calculatedmaximum tip displacement and the Young’s modulus by the equivalent beam model were almost identical to the correspondingmeasured data.Finite element analysis with thermal analogy technique was utilized in the equivalent bimorph beam model tonumerically reproduce the force-displacement relationship of the IPMC actuator.The results by the equivalent bimorph beammodel agreed well with the force-displacement relationship acquired by the measured data.It is confirmed that the equivalentbeam and equivalent bimorph beam models are practically and effectively suitable for predicting the tip displacement,blockingforce and Young’s modulus of IPMC actuators with different thickness and different composite of ionic polymer membrane.     

Design of spread-out Bragg peaks in hadron therapy with oxygen ions

Aim

Design of a numerical method for creating spread-out Bragg peak (SOBP) and evaluation of the best parameter in Bortfeld Model to this aim in oxygen ion therapy.

Uncertainty in positioning ion chamber at reference depth for various water phantoms

Background

Uncertainty in the calibration of high-energy radiation sources is dependent on user and equipment type.

Methods for Physical Characterization of Phase-Separated Bodies and Membrane-less Organelles

Membrane-less organelles are cellular structures which arise through the phenomenon of phase separation. This process enables compartmentalization of specific sets of macromolecules (e.g., proteins, nucleic acids), thereby regulating cellular processes by increasing local concentration, and modulating the structure and dynamics of their constituents. Understanding the connection between structure, material properties and function of membrane-less organelles requires inter-disciplinary approaches, which address length and timescales that span several orders of magnitude (e.g., Ångstroms to micrometer, picoseconds to hours). In this review, we discuss the wide variety of methods that have been applied to characterize the morphology, rheology, structure and dynamics of membrane-less organelles and their components, in vitro and in live cells.