基于DNA遗传优化的正交小波常模盲均衡算法

在上行多用户中继网络中,针对中继协作波束成形与多天线基站联合优化的问题,本文提出了两种不同的但是具有一定相关性的设计方法。在第一种方法中,考虑在接收端SINR约束的情况下,使中继节点总功率最小化;在第二种方法中,研究在中继节点满足一定功率约束的情况下,使接收端SINR最大化。研究发现,基站线性接收器的最优权值矩阵决定于中继节点加权向量,进而可将多变量优化的复杂问题转化为单一变量优化问题。原问题进而可转化为半正定规划问题,可以用内点法方便的解决。仿真结果表明,与通过迭代运用凸优化求多向量的方法相比,该方法性能更优。     

Interactions between Cytochrome c and DNA Strands Self-Assembled at Gold Electrode

In this work, we reported the investigation on the interaction between DNA strands self-assembled at gold electrodes and an electron transfer protein, cytochrome c. We observed that cytochrome c exhibited well-defined electrochemistry in both double-stranded and single-stranded DNA films. This suggested that the electron transfer reaction of cytochrome c arose possibly due to the electron hopping along DNA strands rather than wiring along the double helix. We also compared the heterogeneous electron transfer rate of cytochrome c with that of a ruthenium complex, which further confirmed this mechanism.     

药物抗氧化作用对DNA发光动力学行为的影响

本文应用ＣｕＳＯ４－Ｐｈｅｎ－Ｖｃ－Ｈ２Ｏ２－ＤＮＡ化学发光体系观察药物对发光动力学行为的影响，研究了九种药物对ＤＮＡ损伤的保护作用，并对其药物结构对抗氧化能力的影响进行了分析。发现药物在该系统中的抗氧化作用有三种类型，提示它们可能在体内不同的反应过程中起不同的作用。在该系统中具有抑制ＤＮＡ损伤发光能力的药物，按其作用强弱依次为阿魏酸、丹参素、芦丁，茶多酚、ＳＯＤ、、丹参酮Ⅱ－Ａ，丹皮酚，五味子乙     

Induction of DNA-double-strand breaks by auger electrons from 99mTc complexes with DNA-binding ligands

The potential of certain Auger electron emitting nuclides for systemic radiotherapeutic applications has recently gained much attention. In particular, the ability of several nuclides, including 111In, 125I, and 123I, to induce DNA double-strand breaks (dsb), a good indicator of cytotoxicity, has been extensively studied. However, this ability has never previously been shown experimentally for 99mTc, which, besides the well-known gamma radiation that is used for diagnostic applications, also emits an average of 1.1 conversion electrons and 4 Auger or Coster-Kronig electrons per decay. Owing to the short range of Auger electrons, the radionuclide needs to be located very close to the DNA for dsb to occur. We synthesized two cationic 99mTcI-tricarbonyl complexes with pendant DNA binders, pyrene and anthraquinone. The X-ray crystal structures of the two complexes could be elucidated. Linear dichroism and UV/Vis spectroscopy revealed that the complex with pyrene intercalates DNA with a stability constant, K, of 1.1 x 10(6) M(-1), while the analogous complex with anthraquinone interacts with DNA in a groove-binding mode and has an affinity value of K=8.9 x 10(4) M(-1). We showed with phiX174 double-stranded DNA that the corresponding 99mTc complexes induce a significant amount of dsb, whereas non-DNA-binding [TcO4]- and nonradioactive Re compounds did not. These results indicate that the Auger electron emitter 99mTc can induce dsb in DNA when decaying in its direct vicinity and this implies potential for systemic radiotherapy with 99mTc complexes.     

聚胺与鲑鱼精DNA相互作用中的盐效应

通过浊度、紫外吸收和Zeta电位测定,研究了盐对聚胺与鲑鱼精DNA相互作用的影响。结果表明,加入盐产生屏蔽效应,使体系Zeta电位下降,当c(NaC l)=5 mmol/L时,SPM-DNA体系Zeta电位由0 mV降至-4mV,SPD-DNA体系电位由-2.5 mV降至-4 mV。浊度和紫外吸收结果证明了盐屏蔽效应的存在,并随盐浓度的升高,屏蔽效应增大,且Ca2+、Mg2+的屏蔽作用大于K+、Na+。pH的升高使聚胺-DNA的相互作用减弱。     

含IL-2基因的乙型肝炎病毒DNA疫苗的构建及其免疫效果

目的构建含白细胞介素-2(IL-2)基因的乙型肝炎病毒DNA疫苗,并考察免疫效果。方法将微小病毒内部核糖体进入位点(Internal ribosomal entry site,IRES)基因克隆到质粒pVAX1载体多克隆位点处,再将乙肝病毒表面抗原(HB-sAg)基因和IL-2基因分别连接在IRES基因的两侧,构建出乙肝病毒DNA疫苗pHII。将pHII转染COS-7细胞,进行瞬时表达。大量提取质粒后,按0、2、4周程序免疫BALB/c小鼠,以pVAX1质粒为阴性对照,pVAX/HBsAg质粒为阳性对照。第1针免疫1周后开始眼眶采血,检测血清中HBsAg和HBsAb含量。第1针免疫13周后处死小鼠,用流式细胞仪检测其脾脏T细胞表面CD4+、CD8+分子数量。结果在转染pHII质粒的COS-7细胞上清液中检测到HBsAg和IL-2的表达。实验组和阳性对照组小鼠分别于第1针免疫2、4周后,在血清中检测出HBsAb,但阴性对照组未测出。以上3组均未检测出HBsAg。实验组与阳性对照组相比,产生抗体的时间提前2周,抗体阳转率提高2.5倍,产生抗体的量也提高了近3倍。实验组CD4+分子数量和CD4+/CD8+值均高于阳性对照组。结论乙肝病毒DNA疫苗pHII成功诱导出小鼠的免疫应答,其免疫效果明显优于不含分子佐剂的乙肝DNA疫苗。     

仿石瓷质砖包裹颗粒的制备新工艺

本文分析了当前流行的仿石瓷质砖包裹颗粒制造方法的弊端,并通过改进设备和采用新的工艺方法,研制出仿石效果更佳的产品,这样既提高了颗粒的包裹效率,又降低了生产成本。     

治疗性双质粒HBV DNA疫苗工程菌的中试发酵工艺研究

目的研究双质粒HBV DNA疫苗工程菌的中试发酵工艺。方法首先通过计算质粒拷贝数,检测工程菌DH5α/pS2.S和DH5α/pFP在传代过程中的遗传稳定性,通过摇瓶培养确定培养基组成,再在30L发酵罐内,通过改变培养基成分、培养时间、补料方式,确定最佳发酵参数。并将确定的最佳发酵参数应用于50L发酵罐连续3批中试规模的发酵,同时考察在发酵培养过程中质粒稳定性和超螺旋质粒DNA的比例。结果工程菌DH5α/pS2.S和DH5α/pFP在连续传代30次后,质粒拷贝数保持稳定。确定最佳发酵参数为以甘油为碳源的培养基培养,梯度恒速流加方式补料,培养时间为10h。通过3批稳定发酵,最终可获得湿菌58.0~71.8g/L,质粒含量可达到1.11~1.58mg/g菌,超螺旋质粒DNA的比例达93%以上。结论已建立了稳定的双质粒HBV DNA疫苗工程菌中试发酵工艺,为进一步规模化生产奠定了基础。     

Allelopathic Effects of Volatile Monoterpenoids Produced by <Emphasis Type="Italic">Salvia leucophylla</Emphasis>: Inhibition of Cell Proliferation and DNA Synthesis in the Root Apical Meristem of <Emphasis Type="Italic">Brassica campestris</Emphasis> Seedlings

Salvia leucophylla, a shrub observed in coastal south California, produces several volatile monoterpenoids (camphor, 1,8-cineole, -pinene, -pinene, and camphene) that potentially act as allelochemicals. The effects of these were examined using Brassica campestris as the test plant. Camphor, 1,8-cineole, and -pinene inhibited germination of B. campestris seeds at high concentrations, whereas -pinene and camphene did not. Root growth was inhibited by all five monoterpenoids in a dose-dependent manner, but hypocotyl growth was largely unaffected. The monoterpenoids did not alter the sizes of matured cells in either hypocotyls or roots, indicating that cell expansion is relatively insensitive to these compounds. They did not decrease the mitotic index in the shoot apical region, but specifically lowered mitotic index in the root apical meristem. Moreover, morphological and biochemical analyses on the incorporation of 5-bromo-2-deoxyuridine into DNA demonstrated that the monoterpenoids inhibit both cell-nuclear and organelle DNA synthesis in the root apical meristem. These results suggest that the monoterpenoids produced by S. leucophylla could interfere with the growth of other plants in its vicinity through inhibition of cell proliferation in the root apical meristem.     

CpG-ODN对乙肝核酸疫苗及重组疫苗免疫效果的影响

目的研究CpG寡聚脱氧核苷酸(CpGODN)对乙肝核酸疫苗及重组(CHO细胞)疫苗免疫效果的影响。方法核酸疫苗实验组用CpGODN与乙肝核酸疫苗联合免疫BALBc小鼠,阳性对照组注射核酸疫苗,阴性对照组注射质粒pVAX1;重组疫苗分4个实验组,用CpGODN与不同剂量的重组疫苗配伍后分别免疫BALBc小鼠,阳性对照组注射重组疫苗,阴性对照组注射生理盐水。应用ELISA检测小鼠血清中的抗HBs水平。结果CpG与乙肝核酸疫苗组抗体阳转率比阳性对照组提高3倍,抗体水平提高2倍。CpG与重组疫苗组的阳转率和阳转时间均高于或早于CpG与核酸疫苗实验组。加入CpGODN后,即使重组疫苗用量减少3倍,诱导抗体水平和阳转率均无明显改变。结论CpGODN可提高乙肝核酸疫苗和重组疫苗的免疫效果,并使抗体产生的时间提前。