外源水杨酸对番茄幼苗SDS毒害的缓解效应

采用盆栽实验方法, 研究了十二烷基硫酸钠(SDS)对番茄幼苗若干生理指标的影响以及不同浓度水杨酸对SDS胁迫的缓解效应.结果表明,低浓度的水杨酸能够缓解SDS的胁迫,提高番茄幼苗体内过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性,增加可溶性糖的含量,降低丙二醛(MDA)的积累和质膜的相对电导率.分析认为适当浓度的水杨酸能够缓解SDS对番茄幼苗造成的伤害,增强植株对SDS胁迫的抗性.     

微波辐射水合硫酸铁催化合成乳酸环己酯

研究了以水合硫酸铁为催化剂、乳酸和环己醇在微波辐射下进行酯化反应时,醇酸物质的量比、反应时间、催化剂用量、带水剂用量、微波功率等因素对酯化率的影响.结果表明：当醇酸物质的量比为2∶1、催化剂水合硫酸铁用量为2.5 g、反应时间为25 min、带水剂环己烷用量为6 mL、微波功率为640 W时,酯化率达到91.9%,为该酯化反应的最佳条件.     

乙酰水杨酸合成方法改进

以水杨酸和乙酸酐为原料,以弱酸硫酸铝钾作催化剂可以方便的合成乙酰水杨酸,实验结果表明:反应温度、反应时间、催化剂用量、水杨酸与乙酸酐的比例等因素均有影响,最佳反应条件是:催化剂的用量为0.6g,n(水杨酸)n(乙酸酐)=1.0 2.0,恒温70℃,反应时间为30min,在优化的反应条件下,乙酰水杨酸的产率为77.8%。结果还表明,硫酸铝钾作为催化剂产率高于浓硫酸作催化剂的产率,而且产品色泽为白色,且纯度高。     

弯曲荷载下砂浆的抗侵蚀性能及方法研究

研究了水泥砂浆在荷载作用下抵抗硫酸盐侵蚀的性能.结果表明,弯曲应力状态下的水泥砂浆在高浓度硫酸盐侵蚀务件下侵蚀速度明显增加,应力水平越高,侵蚀速率越快.试验表明,适当掺入聚丙烯纤维能够有效地缓解硫酸盐对水泥砂浆的腐蚀.     

硫酸铵盐析条件对多管藻R-藻红蛋白和R-藻蓝蛋白得率和纯度的影响

 藻胆蛋白是一类用途广泛、市场前景广阔的天然色素蛋白,但分离纯化困难。粗提条件优化对最终获得的藻胆蛋白的得率和纯度影响较大。研究了硫酸铵饱和度、盐析次数、分级盐析对海洋红藻多管藻R-藻红蛋白（RPE）和R-藻蓝蛋白（RPC）提取得率和纯度的影响。结果表明,多管藻RPE和RPC的得率随硫酸铵饱和度的提高而增加,饱和度为60%时得率最高,分别为91.59%、97.98%。饱和度20%的硫酸铵仍能沉淀47.3%的RPE和24.8%的RPC。RPE的纯度随硫酸铵饱和度的提高而降低,但RPC纯度随硫酸铵饱和度的提高而增加,至饱和度为45%时纯度最高,之后随饱和度的提高而缓慢降低。饱和度<40%时,RPE/RPC得率比随硫酸铵饱和度提高而增加;饱和度>40%时,RPE/RPC得率比趋于稳定。硫酸铵盐析2次与盐析1次相比,RPE、RPC的得率降低,但纯度提高。二步法盐析比一步法盐析RPE、RPC的纯度分别提高122.42%、18.67%,但得率降低。因此硫酸铵盐析提取多管藻RPE、RPC时,以饱和度60%为宜,盐析2次,二步法盐析有利于藻胆蛋白纯度的提高,二步法盐析时初次使用的硫酸铵饱和度应<20%。藻胆蛋白盐析条件优化可为藻胆蛋白的进一步分离纯化奠定基础。     

硫酸软骨素(CSB)基质对碳酸钙结晶的影响

根据生物矿化原理,通过CO2的缓慢扩散,用硫酸软骨素(CSB)作为碳酸钙结晶的有效调控剂,与富集在有机/无机界面钙离子的结合,合成了不同形貌的碳酸钙。讨论了CSB基质的浓度,时间,pH对产物的晶型及形貌的影响,研究表明相对于其他因素,CSB的浓度对碳酸钙晶型的生长和形貌的取向具有一定的调控作用。     

Anti herpes simplex virus activity of lactoferrin/lactoferricin – an example of antiviral activity of antimicrobial protein/peptide

One of the most common viral infections in humans is caused by the herpes simplex virus (HSV). It was first effectively treated in the 1970s with the introduction of acyclovir, which is still the most commonly used treatment. Naturally occurring antimicrobial proteins and peptides have also been shown to possess antiviral activity against HSV. This review will focus on the anti-HSV activity of one such protein, lactoferrin, and a small peptide fragment from its N-terminal domain, lactoferricin. Both components have been shown to effectively block entry of HSV into the host cell. In addition to blocking HSV entry, the peptides appear to have immune stimulatory activity, although this is still somewhat controversial. Mode of action studies and knowledge about the anti-HSV activity of lactoferricin have also been successfully employed in the design of new, more specific HSV blockers. Received 25 May 2005; received after revision 24 August 2005; accepted 6 September 2005     

Enhanced heparan sulfate proteoglycan-mediated uptake of cell-penetrating peptide-modified liposomes

Protein transduction domains (PTDs) are used to enhance cellular uptake of drugs, proteins, polynucleotides or liposomes. In this study, functionalized Antennapedia (Antp, aa 43–-58) and HIV Tat (aa 47–57) peptides were coupled to small unilamellar liposomes via thiol-maleimide linkage. Modified liposomes showed higher uptake into a panel of cell lines including tumor and dendritic cells than unmodified control liposomes. Liposome uptake was time and concentration dependent as analyzed by flow cytometry and live-cell microscopy. At least 100 PTD molecules per small unilamellar liposome (100 ± 30 nm) were necessary for efficient translocation into cells. Cellular uptake of PTD-modified liposomes was 15- to 25-fold increased compared to unmodified liposomes and was inhibited by preincubation of liposomes with heparin. Glycosaminoglycan-deficient CHO cells showed dramatically reduced cell association of PTD-modified liposomes, confirming the important role of heparan sulfate proteoglycans in PTD-mediated uptake. Antp-liposomes used as carriers of the cytotoxic drug N⁴-octadecyl-1--D-arabinofuranosylcytosine-(5- 5)-3-C-ethinylcytidine showed a reduction of the IC₅₀ by 70% on B16F1 melanoma cells compared with unmodified liposomes. PTD-functionalized liposomes, particularly Antp-liposomes, represent an interesting novel carrier system for enhanced cell-specific delivery of a large variety of liposome-entrapped molecules.Received 16 April 2004; received after revision 13 May 2004; accepted 25 May 2004     

从烂版废液中回收硫酸铜新法

提出了从烂版废液中回收硫酸铜的新工艺．硫酸铜质量（纯度）在９８％以上，原料中铜近于定量回收，无三废污染，分析了工业应用的可能性