体外源冲击波粉碎肾结石研究

简要评述了液电式冲击波粉碎肾结石机中的碎石效应。为达到在治疗中少副作用,在线性和准线性近似的基础上计算并分析了液电式冲击波粉碎肾结石机中的反射聚焦声场。给出了对于连续波和脉冲波在近场和远场中轴向和侧向声压波形分布,指出在单频波情况下,在焦平面及其平行面中声强与焦斑半径的平方成反比,声压幅度分布为正态函数和近似正态函数分布。对于脉冲情况,导出波形、波前和波幅的关系,给出了数值计算结果,使与实测波形相比较。最后分析讨论了非线性效应等对脉冲波形的影响。

外源NO供体SNP对PEG模拟干旱胁迫下高羊茅种子萌发及幼苗抗性生理的影响

以高羊茅为研究对象,采用不同PEG模拟干旱处理(CK、10%PEG、0.1 mmol/L SNP+10%PEG、1.0 mmol/LSNP+10%PEG等)方法,就外源NO供体SNP对高羊茅种子的萌发、幼苗生长及抗逆性的影响进行了探讨。结果表明,在PEG模拟干旱胁迫下,高羊茅种子的发芽率、发芽势、发芽指数、活力指数和幼苗叶绿素含量较对照呈下降趋势,而幼苗丙二醛(MDA)、脯氨酸、可溶性糖、超氧阴离子(O2.-)和过氧化氢(H2O2)含量呈上升趋势,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性则呈现先升高后降低的趋势。上述结果说明PEG模拟的干旱胁迫,使得高羊茅在种子萌发及幼苗生长过程中遭受逆境胁迫,且生长发育受到显著抑制。经外源NO供体SNP处理后,模拟干旱胁迫下的高羊茅种子发芽率、发芽势、发芽指数、活力指数和幼苗叶片叶绿素、脯氨酸、可溶性糖含量及SOD、POD、CAT活性均显著升高,而幼苗叶片MDA、O2.-和H2O2含量显著下降,说明外源NO供体SNP处理后使PEG模拟干旱胁迫下高羊茅的生长发育得到了促进,减轻了干旱胁迫对高羊茅造成的伤害,提高了植株的整体抗旱性。通过对比几种不同SNP浓度,结果说明0.1 mmol/L SNP对PEG模拟干旱胁迫下高羊茅种子萌发及幼苗的保护效应较为显著。

脂质体介导外源基因体外转染牛胎儿成纤维细胞条件的优化

通过脂质体(FuGENE-6)介导,将真核表达载体pEGFP-C1成功导入体外培养的牛胎儿成纤维细胞,探讨影响外源基因转染效率的参数,如DNA和脂质体的用量、转染的细胞数量以及细胞暴露于DNA与脂质体复合物的时间长度。通过实验发现,绿色荧光蛋白(greenfluorescentprotein,GFP)基因的表达随DNA、脂质体量的增加而增加,延长细胞暴露时间反而使转染效率下降,转染细胞数适当才能得到较高的转化率。

外源NO供体对小麦离体叶片过氧化氢代谢的影响

分析了外源一氧化氮 (nitricoxide ,NO)供体硝普钠 (sodiumnitroprusside ,SNP)对离体小麦 (TriticumaestivumL .)叶片过氧化氢 (H2 O2 )含量及其清除酶活力的调节作用。不同浓度的SNP (1mmol/L和 5mmol/L)处理 3 0min内 ,离体小麦叶片H2 O2 含量均有一个显著上升的过程 ,同时过氧化物酶 (POD)活力受到显著抑制 ,而过氧化氢酶 (CAT)活力则轻微下降 ;处理 3 0min到 2 4 0min时 ,POD活力的抑制状态基本维持不变 ,而CAT活力开始恢复上升 ,H2 O2 含量也相应地开始下降。粗酶液的体外实验也表明 ,SNP对POD和CAT的抑制类型不同 ,前者可能是不可逆抑制 ,后者则可能是可逆抑制。因此NO可通过对POD和CAT的不同抑制作用来调节小麦叶片内源H2 O2

外源激素对芦荟外殖体芽分化的影响

以库拉索芦荟（Aloe vera)的顶芽和腋芽为外殖体，采用ＭＳ培养基添加不同浓度激素（6-BA、KT、ZT、NAA、２,4-D、GA3)进行培养试验，探讨外源激素对芦荟外殖体芽分化的影响。结果表明：BA最有利于芦荟芽分化，其次是KT、ZT对芦荟芽分化不敏感；NAA对芽生根诱导能力较2,4-D强，生根培养以MS+NAA 0.25mg/L+AC（活性炭）0.20％为最适，生根苗根系发达且移栽成活率高；低浓度糖对分化有利，高浓度的糖对生根有利。

离子束介导外源全DNA转化拟南芥菜的诱变效应

用 30kev的Ar+ 离子 ,以 1.5× 10 17ions/cm2 的注入剂量分别介导外源拟南芥菜 (Lansberg生态型 )、甘蓝、红甜菜和芦荟的全DNA转化拟南芥菜种子 (Columbia生态型 )。转化当代营养期表型变异率与外源供体和转化受体的亲缘远近没有必然的联系 ,而低育性株率却随着外源供体亲缘关系的从近到远 ,呈现一种从低到高再变低的变化趋势。从低育性株后代中选育出 2个稳定的突变体 ,该突变体不但保持了其亲本的低育性 ,而且其他性状也有较显著的变异 ,如株型、叶型等。

外源硝普钠对盐胁迫下牛大力胚根生理指标的影响

以牛大力种子胚根为试验材料,通过测定可溶性糖、可溶性蛋白、脯氨酸、丙二醛含量,POD、SOD活力等生理指标,研究盐胁迫及外源SNP对盐胁迫下牛大力胚根的生理指标的影响。结果表明:Na+浓度由0到50 mmol·L^-1时,牛大力胚根可溶性糖、可溶性蛋白和脯氨酸含量增加,而随着盐浓度升高,各指标含量均出现不同程度的下降;牛大力胚根丙二醛含量随着盐浓度增大呈上升趋势;牛大力胚根SOD和POD活力随着盐胁迫浓度升高呈先升高再下降的趋势;添加外源SNP浓度由0到40μmol·L^-1时能增加可溶性糖、可溶性蛋白、脯氨酸含量,随着外源SNP浓度增加,各指标出现不同程度的下降;添加外源SNP浓度由0到40μmol·L^-1时牛大力胚根丙二醛含量下降,随着SNP浓度增大丙二醛呈上升趋势;牛大力胚根SOD和POD活力随着外源SNP浓度升高呈先升高再下降的趋势。本试验表明,盐胁迫对牛大力胚根生理指标有一定影响,适量添加外源SNP能缓解盐胁迫对牛大力胚根的伤害。

补充NO前体L-Arg对耐力训练大鼠疲劳状况的影响

目的 :(1)观察耐力运动和补充外源性NO前体L -Arg(左旋精氨酸 )对机体各组织NO生成能力的影响 ;(2 )观察补充外源性NO前体L -Arg对机体运动疲劳状况的影响。方法 :将 30只SD大鼠随机分成安静组、运动对照组和运动用药组 ,运动组大鼠进行 4周跑台耐力训练和一次力竭运动 ,其中运动用药组每天给予 4 0mg每kg体重L -Arg灌胃 ,测定了力竭运动后即刻大鼠组织NO生成能力以及血清生化指标的变化。结果 :(1)所有运动组大鼠血清、肌肉、心肌、肝脏NOS活性均有升高趋势 ,尤其以血清、心肌和肝脏的升高具有显著性意义 ;(2 )运动用药组大鼠血清血尿素 (BUrea)、谷丙转氨酶 (ALT)、乳酸脱氢酶 (LDH)均较运动对照组有升高趋势。结论 :(1)补充外源性L -Arg对机体整体生成NO的能力 ,尤其是心脏等器官生成NO的能力可能有促进作用 ;(2 )补充外源性NO前体L

遮光胁迫下外源NO对盆栽长春花土壤养分含量及幼苗生长特征的影响

为探究遮光胁迫下施加外源NO供体(硝普钠,SNP)对土壤养分变化和长春花(Catharanthus roseus)幼苗生长的影响,设置4种处理(全光照生长为对照、外施SNP、遮光、遮光+外施SNP联合处理),分析盆栽土壤中C、N、P养分含量和土壤理化指标,测定幼苗的株高、节间距、茎直径、叶长、叶宽、叶面积、全株鲜(干)质量。结果表明:遮光和外施NO联合处理下,土壤含水量、土壤pH和土壤有机碳含量显著增加(P<0.05),而土壤中全氮、碱解氮、全磷和速效磷含量增加但不显著,土壤C/N和C/P值升高,且C/N值达到显著水平(P<0.05);相关性分析结果表明:土壤pH与有机碳含量呈显著正相关性(P<0.05),土壤有机碳含量与株高、叶片鲜质量之间呈显著正相关(P<0.05)。说明施加外源NO能促进遮光胁迫下土壤pH升高,改变土壤中有机碳含量,增加C/N值,改善土壤肥力,促进叶片生长发育,增加长春花的生物量,为长春花的科学平衡施肥和生物碱含量的积累提供一定依据。

基于第三体的制动材料摩擦磨损行为研究进展

制动系统是交通运输和工业设备的重要组成部分,在高速、高载、高温的摩擦工况下,接触表面会因剧烈磨损而产生磨屑,并在复杂的摩擦化学反应下形成厚度为几微米至几十微米的摩擦膜,其被称为“第三体”。制动时,第三体经历了塑性变形、氧化、粘附、分层等变化,对制动材料的摩擦磨损性能产生重要影响,即制动材料的摩擦磨损性能取决于第三体的性质。因此,掌握第三体的组织结构、形成及演变机制有利于对制动材料摩擦磨损性能及机理的深入研究,从而为新型制动材料的研制提供依据。第三体的早期研究主要集中在采用SEM、EDX、TEM等手段分析其组成、形成与运动机制方面,并取得了较为丰富的成果。随着表征方式的发展,研究人员开始尝试从应力、纳米结构、化学键等更为微观、本质的角度阐述第三体的运动、演化和作用机制,进一步将第三体与摩擦条件及磨损机理相关联。第三体对材料摩擦磨损性能影响的研究,已由传统的摩擦系数、磨损率逐步扩展到选择性转移、界面化学反应、摩擦功率损耗等方面。但上述研究大多采用非原位法,只能间接获取摩擦表面信息,存在局限性和滞后性。为分析第三体的动态特性,近些年开发了外源第三体实验法和基于第三体的建模仿真,对澄清第三体中各组元作用、探索第三体微观演化规律具有重要意义,特别是以离散元法(DEM)、可移动元胞自动机法(MCA)为代表的非连续介质模拟,可针对第三体的位移变化、力学性能变化及受力状况进行大规模仿真。本文归纳了第三体组成、形成和运动机制,阐述了第三体对制动材料摩擦磨损性能的影响,总结了外源第三体实验法和第三体建模仿真方面的研究进展,重点对可移动元胞自动机法进行了介绍,最后结合当前第三体研究中出现的问题提出了改进方向,并对未来发展趋势进行了展望。

Meiotic Behavior of 1BL/1RS Translocation Chromosome and Alien Chromosome in Two Tri-genera Hybrids

The behavior of wheat-rye translocation chromosome and alien chromosome including Thinopyrum and Haynaldia chromosome at meiosis was investigated in two hybrids by fluorescence in situ hybridization (FISH). Misdivision of translocation chromosome at anaphase I and rye chromatin micronucleus at tetrad stage were observed, A plant with one normal 1BL/1RS translocation chromosome and one 1BL/1RS translocation chromosome deleted about 1/3 of rye chromosome arm in length was identified. One plant with wheat-Thinopyrum non-Robertson translocation chromosome was also detected in the F-2 population of Yi4212 x Yi4095. That could be the results of unequal misdivision of wheat-rye 1BL/1RS translocation chromosome and Thinopyrum chromosome during meiosis. No interaction between translocation chromosome and alien chromosome at meiosis was supported by the data of the distribution frequencies of translocation chromosome and Thinopyrum or Haynaldia chromosome in the progeny of two hybrids. The results may be useful to cultivate new germplasms with different length of rye 1R short arm and wheat-alien non-Robertson translocation tines under wheat background.

黑麦优良基因在小麦育种中的应用

黑麦属蕴藏着许多对改良小麦有用的基因资源,将黑麦的优良基因导入小麦不仅可以拓宽小麦的遗传基础,而且可以有效改良小麦的产量、品质、抗性及适应性等性状。为了了解目前黑麦在小麦遗传育种中的研究现状,本文从黑麦基因导入小麦的途径、黑麦基因资源在小麦中的鉴定以及黑麦基因资源在小麦中的应用前景三方面总结论述了黑麦优良基因在小麦育种中的应用,以期促进黑麦优良基因向小麦中转移,深入开拓和利用黑麦基因资源。

Using Subtracted AFLP to Efficiently Mark an Alien Chromosome Fragment in Wheat Background

为解决AFLP中样品间共同片段对多态性片段识别的干扰 ,作者建立了一种“减法AFLP”标记技术 ,并运用这种技术成功对小麦中的外源染色体片段进行了标记。运用该技术 ,样品间的共同扩增片段显著减少 ,在非变性聚丙稀酰胺凝胶上带型差异十分明显 ,多态性片段很容易分辨。其真实性通过将其中两条成功转换成外源染色体片段特异的SCAR标记得到了验证。减法AFLP标记技术的建立为标记作物中的外源染色体片段提供了一种有效手段。

Transmission Electron Microscopy Observation of Different Callus Structures in Heiya No.14

[ Objective] The aim was to observe the ultrastructure of different callus structures in Heiya No. 14 by transmission electron microscopy. [Methods] Sample preparation and observation were both carried out by conventional transmission electron microscopy. [ Results] It was showed by transmission electron microscopy that the initial callus cells had a large central vacuole, which squeezed its cytoplasm to be a thin layer around the brim of cell, Meanwhile the nuclear was also squeezed to distribute in the corner of cell, but its nucleolus could be still observed; Compared embryogenic callus with initial callus, its cell wall became thick, and many starch grains and chloroplasts including starch grains could be observed in the cytoplasm area of cell membrane; In non-embryoenic callus, no organelles except for the vacuole could be observed; In browning callus, there was almost no organelles in cells. [ Conclusion] There are significant differences in different types of flax callus at the cell ultrastructure level, which can be as an index for reflecting the differentiation ability of callus cell.

EFFECT OF STAT3 SPECIFIC SHRNA EXPRESSION VECTOR ON PROLIFERATION AND APOPTOSIS OF HUMAN PANCREA-TIC CANCER CELLS

Objective To construct signal transduction and activators of transcription 3 (STAT3) short hairpin RNA (shRNA) expression vector and to investigate its inhibitory effects on STAT3 expression, cell proliferation and apoptosis of human pancreatic cancer. Methods Three pairs of hairpin-like oligonucleotide sequences specific for human STAT3 gene were designed and synthesized. The annealed oligonucleotide fragments were subcloned into pRNAT-U6.1/Neo plasmid. The STAT3 shRNA expressing vectors were confirmed by PCR and DNA sequencing. STAT3 mRNA and protein expression were examined by using reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. MTT assay and flow cytometry were performed to detect the state of cell proliferation and cell apoptosis, respectively. Results PCR and DNA sequencing showed that the oligonucleotide fragments were correctly inserted into pRNAT-U6.1/Neo plasmid. STAT3 expression and cell proliferation in the transfected cells was inhibited significantly by three STAT3 shRNA expressing vectors (P<0.05). ConclusionSTAT3 shRNA expression vector can effectively inhibit the expression of STAT3. Silencing of STAT3 with RNAi can significantly inhibit the proliferation and promotes the apoptosis of pancreatic cancer cells and may provide a novel therapeutic target for treating pancreatic cancer.

Beyond Transformational Change： Incremental Transformational Change in Institutions

Much has been written and researched about transformational change and the exogenous events that result in radical institutional transformation （Di Maggio ＆ Powell, 1983; Hannan＆ Freeman, 1989; Fligstein, 1996; Zorn, Dobbin, ＆ Kwok, 2006）. Accounts are provided of external agents disturbing the existing stasis of the institution and transforming the institution into something else that reflect a new paradigm or set of interests. Often, what is neglected in these accounts is what fractures exist in the original institution that would make them vulnerable and allow penetration by exogenous influences. Mahoney and Thelen （20 l 0） went beyond a general model of change that described the collapse of one set of institutional norms to be replaced by another. The model of change they propose takes into account both exogenous as well as endogenous factors as being the source of institutional change. They went on to state a view that transformation change as being a result of abrupt, wholesale breakdown needs to be rethought to include incremental, endogenous shifts in thinking that can often result in fundamental transformations.

Exogenous phosphatidylethanolamine induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway

AIM: To investigate the signaling pathways implicated in phosphatidylethanolamine (PE)-induced apoptosis of human hepatoma HepG2 cells. METHODS: Inhibitory effects of PE on human hepatoma HepG2 cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle, apoptosis and mitochondrial transmembrane potential (ΔΨm) were analyzed by flow cytometry. Immunocytochemical assay and Western blotting were used to examine Bcl-2, Bax and caspase-3 protein levels in HepG2 cells treated with PE. RESULTS: PE inhibited the growth of HepG2 cells in a doseand timedependent manner. It did notaffect the cell cycle, but induced apoptosis. PE significantly decreased ΔΨm at 0.25, 0.5 and 1 mmol/L, respectively, suggesting that PE induces cell apoptosis by decreasing the mitochondrial transmembrane potential. The Bcl-2 expression level induced by different concentrations of PE was lower than that in control groups. However, the Bax expression level induced by PE was higher than that in the control group. Meanwhile, PE increased the caspase-3 expression in a doseand time-dependent manner. CONCLUSION: Exogenous PE induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway.

In vitro Culture of Early Rabbit Embryos Injected with Foreign Gene and Its Retention

Fertilized rabbit eggs injected with SMTPGH gene were cultured in vitro and retention of theinjected gene was studied using PCR technique and nonradioactive labelling methed. In a mediumof TC199 + 10% FCS, three quarters of the fertilized eggs developed to the blastocyst stage. Noapparent change of the injected gene was found before the 8-cell stage, after which it was eitherintegrated into the chromosome of the host or lost gradually. But finally, the retention rate of theinjected gene should be equal to its integration rate.

Effect of Different Concentration of Cytokinins, Carbon Source and Agar on in vitro Propagation of Dahlia sp. through One Single Node

An efficient in vitro protocol for mass production of shoot of Dahlia was developed by using node explant, various carbon sources such as sucrose, glucose, fructose and galactose. Agar concentrations and various growth regulators on in vitro shoot multiplication of Dahlia were studied in the present investigation. The nodal explant from the gardens grown plant were used as testing plant material to develop an efficient protocol for mass propagation of exotic Dahlia to enhance their production for growers and the local markets. This study determined the effect of different carbon sucrose concentrations and gelling agent on in vitro propagation of Dahlia, different carbon sources （sucrose, glucose, fructose and galactose） were investigated, each sugar was added individually to the MS culture medium at the concentrations of 15, 30 and 45 g·L^-1, respectively. Culture medium of each treatment was supplemented with 1,5 mg·L^-1 BA ＋ 1.5 mg·L^-1Kin ＋ 7,0 g·L^-1 agar. The highest number of shoots （7.00）, number of leaves （11.50）, number of node （6.75） and shoot length （8.24 cm） was obtained on MS medium supplemented with 30 g·L^-1 glucose. The least number of shoots （3.38）, number of leaves （5.00）, number of node （3.13） and the least shoot length （2.96 cm） was obtained on 45 g·L^-1 galactose and the least shoot length （2.29 cm） was observed on MS medium with free carbon sources. While the medium with 30 g·L^-1 glucose and 8 g·L^-1 agar gave the highest number of shoots （7.13）, number of leaves （10.75）, number of node （7.13） and shoot length （8.18 cm）. However, the least number of shoots （1.50）, number of leaves （1.88）, number of node （1.63） and the least shoot length （1.26 cm） was obtained with 30 g·L^-1 galactose and 12 g·L^-1 agar. Rooting was readily achieved upon transferring the microshoots onto MS medium supplemented with 0.1 mg·L^-1 IBA, IAA and NAA and 30 g·L^-1 （w/v） different types of carbon sources. The percentage of rooting was less （71.88%） on MS medium containing IAA as compared with IBA or NAA. While the medium having 30 g·L^-1 glucose with 0.1 IBA or NAA mg·L^-1, give the highest percentage of root （100%）, and the highest number of root （3.88） and root length （3.56 cm） was obtained on MS medium containing 30 g·L^-1 glucose with 0.1 mg·L^-1 IBA. More than 98% of rooted plantlets were established in the greenhouse.