可阻止的

Vitamin C can boost immunity and can prevent the formation of a strong carcinogen nitrosamine.

而维生素C可增强免疫力，能阻止强致癌物质亚硝胺的形成。

This toxic effect was completely blocked by copper-zinc superoxide dismutase + catalase (SOD/catalase) or 〓-nitro-L-arginine methyl ester or oxyhemoglobin .

由〓引起的LDH释放可被超氧化物岐化酶（superoxide dismutase，SOD）+过氧化氢酶、NOS抑制剂L-NAME和氧合血红蛋白完全阻止。

O'Neil is attendant going up also is the move that be surrounded by the player of numerous cherish against the law, but this also cannot prevent his shoot a basket, grab a rebound, buckle basket.

奥尼尔在场上也是被众多心怀不轨的球员包围着，可这也不能阻止他投篮，抢篮板球，扣篮。

However, the use of oxygen is a benign intervention which, by raising oxygen tension, may prevent sickling in peri-occlusive sites.

然而，供氧治疗效果较好，可提高氧张力，从而阻止阻塞部位周围的镰状化。

Identified in the human cell surface protein molecules Teth Juan erin, HIV particles can be attached to the mother cell's outer membrane, the mutant virus to prevent proliferation.

在人类细胞表面确定蛋白质分子teth鄄erin，可将艾滋病病毒颗粒附着在母细胞的外膜上，阻止病毒突变株扩散。

The results show that the formation of stable radical AH-R*between the antioxidant and the carbon-centred free radical R*from fat may be a main mechanism of the antioxidation to retard lipid rancid, and dihydrotanshinone I can also act as an antioxidant by donating a hydrogenatom to R*, becoming themselves an unreactive radical A*.

结果表明，抗氧化剂与油脂中碳中心自由基复合成稳定自由基，可能是丹参醌抑制或阻止油脂氧化酸败的主要途径，双氢丹参醌Ⅰ也可借助释放活泼H（本身转化成稳定自由基A*）有效清除R*。

The results show that the formation of stable radical AH-R* between the antioxidant and the carbon-centred free radical R* from fat may be a main mechanism of the antioxidation to retard lipid rancid, and dihydrotanshinone Ⅰ can also act as an antioxidant by donating a hydrogenatom to R*, becoming themselves an unreactive radical A*.

结果表明，抗氧化剂与油脂中碳中心自由基复合成稳定自由基，可能是丹参醌抑制或阻止油脂氧化酸败的主要途径，双氢丹参醌Ⅰ也可借助释放活泼H（本身转化成稳定自由基A*）有效清除R*。

Specifically, itcontains 8 chapters.In chapter 1, the formation, structures, properties and the futureprospect of liposome were thoroughly reviewed;In chapter 2, the stibility and permeability of phopholipid -eleostericacid liposome were studied together with the effect of polymerizationof eleostearic acid. This membrane system was very sensitive to 〓,the effect of 〓 was clarified to increase the aggregation/fusion ofliposomes and made the permeability of mixed liposomes much higher;In chapter 3, two polymerizable conjugated diyne bolaamphiphiles were synthesized. They could form very stable mixed liposome, andthe diyne could be polymerized by UV light in bilayer liposomes, as aresult, the stability of mixed liposome against solvent or surfactantafter polymerization were enhanced. In chapter 4, two kinds of amphiphilic amino acids were synthesized andstable liposomes were formed therefrom After the condensationpolymerization of amino acid in bilayer liposomes, stable polypeptide liposomes were obtained, which had lower phase transition temperatureand higher permeability.In chapter 5, four kinds of glycolipids were synthesized and theiraggregation behavior in water was comparied. When incorporated intophospholipid bilayer membranes, they could increase the phase transitiontemperatures and inhibit the aggregation and fusion of mixedliposomesat lower temperature.In chapter 6 and 7, three kinds of steroidal bolaamphiphiles withdifferent chain lengths were synthesized. Incorporation of steroidalmoiety to the center of lipid bilayer membrane obviously increased themobility of lipid membrane and shifted Tc to lower temperature side incomparasion with cholesterol. The bolaamphiphile which was shorter thanthe hosted lipid bilayer membrane thickness influenced the lipid packingmore obviously.

全文共分8章：第一章对脂质体的形成、结构、性质及展望进行了较为详细的文献综述；第二章研究了磷脂-桐酸脂质体的稳定性，通透能力及桐酸的聚合对这些性质的影响；磷脂-桐酸混合脂质体为一类对〓灵敏的脂质体，〓的作用首先是使脂质体集聚然后使脂质体融合，并加速内包荧光物的释放；第三章通过合成两种可聚合共轭双炔双极性双亲分子DDCA，DDOL，研究了共双炔分子在双分子层脂质体膜上的聚合及对脂质体性质的影响，聚合可以提高脂质体相对于溶剂及表面活性剂的稳定性；第四章合成了两类氨基酸为极性基团的双亲分子，它们均可以在超声下形成稳定的脂质体结构；氨基酸基团可以在脂质体上进行缩聚反应，若聚合后脂质体表面仍有足够的亲水能力，则可得到稳定的多肽型脂质体；聚合后脂质体的相变温度降低，通透能力增加；第五章合成了四种亲水基团为单糖基的双亲分子GL-l，GL-2，GL-3， GL-4，研究了它们在水中的分散情况、集合体形态与分子结构的关系；在DMPC双分子层膜中加入糖脂分子可以使脂质体的相变温度提高，阻止脂质体在低温放置时的集聚与融合；第六章-第七章合成了三种不同碳链长度的双极性含胆甾环双亲分子 CL-1，CL-2，CL-3；它们可以象胆固醇一样与磷脂混合形成稳定脂质体，胆甾环基团位于脂质体双分子层膜的中间；与胆固醇的作用相反，它们可以增加磷脂双分子层膜的流动性，降低混合脂质体的相变温度；三种分子的作用与其碳链长度和磷脂双分子层膜的厚度有关，比膜厚度短的分子影响最大。

Part one: Investigation the effect of curcumin on nephrotoxic sera nephritis in ratsObjective To observe the effect of curcumin on the urine pro

电镜结果显示，姜黄素可明显阻止肾小球上皮细胞足突融合及基底膜的增厚趋势，抑制系膜细胞、内皮细胞

Glioma is still one of refractory disease in the neurosurgical field; the development of new primary and adjuvant treatment is vital. Recently, the gene therapy of glioma is developed rapidly and there are many methods about the gene therapy that include: suicide gene therapy, immunologic gene therapy, drug resistangce gene therapy, angiostatin gene therapy and so on. The sucide gene therapy is the most potential approach of antitumer, these nonmammalian genes encode enzyme that convert nontoxic prodrugs into highly toxic metablites. Cells transfected with suicide genes are targeted for specific negative selection, witch can be induced by administrtion of the corresponding produg. Among the enzyme/produg combinations, two of the best characterized system are herpes simplex virus thymidine kinase /ganciclovir and Escherichia coli cytosine deaminase /5-flourocytosine (5-FC). The formor can convert the antiviral nucleoside analogs acyclovir , ganciclovir to their nucleoside monophosphate derivatives, the monophosphate forms are subsequently phosphorylated by endogenus cellular kinases to triphosphates, these molecules are potent inhibitors of DNA synthesis.

近年来脑胶质瘤的基因治疗发展迅速，应运而生的方法有自杀基因、免疫基因、多药耐药基因以及抗血管生成基因等，其中自杀基因被认为是最有前景的基因治疗方法，它又称病毒介导的酶／药物前体疗法，是利用转基因技术将哺乳动物细胞中所不含有的自杀基因转入到哺乳动物肿瘤细胞中，该基因表达的产物可将无毒的药物前体转化为毒性药物，从而选择性杀伤该肿瘤细胞，常用的自杀基因有单纯疱疹病毒-胸苷激酶基因和大肠杆菌胞嘧啶脱氨酶基因，前者催化无毒性抗病毒核苷类似物如丙氧鸟苷、无环鸟苷等成为单磷酸核苷衍生物，然后在内源性细胞激酶作用下转化为具有明显毒性的三磷酸核苷，作为DNA合成链的终止剂和DNA合成酶的抑制剂，干扰细胞DNA的合成；后者编码的胞嘧啶脱氨酶可催化5-氟胞嘧啶（5-FC）脱氨成为5-氟尿嘧啶（5-FU），然后代谢为有毒性的5-氟尿嘧啶-5′三磷酸（5-FUTP）和5-氟-2′脱氧尿嘧啶-5′磷酸（5-FdUTP），5-FUTP通过与UTP竞争性结合而抑制mRNA和tRNA的合成，5-FdUTP则作用于胸苷合成酶，导致TMP衰竭而阻止DNA的合成，最终诱导肿瘤细胞凋亡。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。